U.S. patent number 3,998,786 [Application Number 05/363,800] was granted by the patent office on 1976-12-21 for process for preparing aromatic polyimides, polyimides prepared thereby.
This patent grant is currently assigned to University of Notre Dame du Lac. Invention is credited to Gaetano Francis D'Alelio.
United States Patent |
3,998,786 |
D'Alelio |
December 21, 1976 |
Process for preparing aromatic polyimides, polyimides prepared
thereby
Abstract
A process for preparing substantially completely cyclized
aromatic polyimides, either monomeric, oligomeric or polymeric, is
provided. The process involved the reaction of a mixture of at
least one tetracarboxylic acid dianhydride and at least one
aromatic diamine in at least one aromatic phenol, preferably
cresols, in the presence of an organic azeotroping agent such as a
cyclic hydrocarbon, preferably benzene, until substantially all of
the water of reaction is eliminated. Other monomers, e.g., a
monoamine or an .alpha.,.beta.-carboxylic acid monoanhydride can be
added to the mixture so as to provide reactive end groups,
preferably olefinically terminated, which will enable the polyimide
to cure by coupling together by addition or condensation thereby
increasing molecular weight with little or no by-product. After the
water is removed, it is preferred that the azeotroping agent be
removed and then the polyimide increased in molecular weight by
heating in the aromatic phenol. The polymer can then be isolated by
concentration or precipitation as a powder, or the polymer in
solution can be used to prepare coatings on various substrates.
Inventors: |
D'Alelio; Gaetano Francis
(South Bend, IN) |
Assignee: |
University of Notre Dame du Lac
(Notre Dame, IN)
|
Family
ID: |
23431786 |
Appl.
No.: |
05/363,800 |
Filed: |
May 25, 1973 |
Current U.S.
Class: |
526/70; 525/422;
525/925; 526/67; 526/71; 528/125; 528/128; 528/172; 528/188;
528/208; 528/229; 528/317; 528/351; 528/353; 546/66; 524/741;
525/436; 525/928; 526/259; 526/285; 528/126; 528/170; 528/179;
528/207; 528/222; 528/322; 528/352; 546/37; 548/455; 526/263 |
Current CPC
Class: |
C08G
73/101 (20130101); C08G 73/1057 (20130101); C08G
73/106 (20130101); C08G 73/1064 (20130101); C08G
73/1067 (20130101); C08G 73/1071 (20130101); Y10S
525/928 (20130101); Y10S 525/925 (20130101); Y10T
428/31721 (20150401) |
Current International
Class: |
C08G
73/00 (20060101); C08G 73/10 (20060101); C08G
073/10 (); C08G 073/12 () |
Field of
Search: |
;260/47CP,47UA,28TF,78UA,33.4P,65,63N,63R,46.5E,49,67R,3.4N |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Lee; Lester L.
Claims
What is claimed is:
1. A process for the preparation of a substantially cyclized
polyimide of the formula: ##STR21## wherein Ar is a divalent
aromatic oganic radical,
Ar' is a tetravalent aromatic organic radical, the four carbonyl
groups being attached directly to separate carbon atoms and each
pair of carbonyl groups being attached to adjacent carbon atoms in
the Ar' radical,
A is NH.sub.2 --, ##STR22## where R" is defined hereinafter, A' is
--R", --ArNH.sub.2, ##STR23## where R" is defined hereinafter, and
n is 0 or a positive integer of at least one, soluble in a phenol
which comprises:
1. reacting a reaction mixture of at least one tetracarboxylic acid
dianhydride of the formula: ##STR24## wherein Ar' is as defined
above, and at least one aromatic diamine of the formula:
wherein Ar is as defined above, at a molar ratio of dianhydride to
diamine in the range of m to m + 1:m to m + 1 where m is a positive
integer of at least one and as high as n in formula (A), with the
proviso that when the ratio of dianhydride to diamine is m + 1:m,
the reaction mixture contains 0 or 2 moles of a monoamine of the
formula R"NH.sub.2 wherein R" is a hydrocarbon radical of 1 to 12
carbon atoms which is saturated, has olefinic unsaturation or
acetylenic unsaturation, and --CN, --CHO or --CH=NR" substituted
derivatives thereof, ##STR25## where each R' is hydrogen or
--CH.sub.3 in the presence of at least one organic azeotroping
agent which:
a. gives a water azeotrope having a boiling point less than
95.degree. C at atmospheric pressure,
b. is non-reactive with the dianhydride and the diamine, and
c. separates from water as a distinct phase, said reaction
conducted at a temperature less than 140.degree. C and below the
boiling point of said phenol and higher than the boiling point of
said azeotroping agent with the vapor phase temperature being
between that of the water azeotrope and no higher than 95.degree.
C
2.
2. removing water of reaction and the azeotroping agent from the
reaction mixture as a water azeotrope and
3. returning quantities of azeotroping agent to the reaction
mixture to maintain the temperature and reaction mixture volume
substantially
constant. 2. The process of claim 1 wherein the phenol is m-cresol
or a mixture of m-cresol and its isomers.
3. The process of claim 1 wherein the organic azeotroping agent is
a cyclic hydrocarbon having 6 to 8 carbon atoms.
4. The process of claim 3 wherein the cyclic hydrocarbon is an
aromatic hydrocarbon.
5. The process of claim 4 wherein the aromatic hydrocarbon is
benzene or toluene.
6. The process of claim 1 wherein Ar' is a tetravalent radical
containing at least one ring of six carbon atoms, said ring
characterized by benzenoid unsaturation.
7. The process of claim 6 wherein Ar is a divalent benzenoid
radical selected from the group consisting of ##STR26## and
multiples thereof connected to each other by R.sup.IV wherein
R.sup.IV is selected from the group consisting of --CH=CH--, an
alkylene chain of 1-3 carbon atoms, ##STR27## wherein R.sup.V and
R.sup.VI are selected from the group consisting of alkyl of 1 to 6
carbon atoms a aryl of 6 carbon atoms
8. The process of claim 7 wherein the phenol is m-cresol or a
mixture of m-cresol and its isomers and the organic azeotroping
agent is a cyclic hydrocarbon of 6 to 8 carbon atoms.
9. The process of claim 8 wherein the cyclic hydrocarbon is an
aromatic hydrocarbon.
10. The process of claim 7 wherein n is at least 4, A is
##STR28##
11. The process of claim 10 wherein R" is allyl, styryl, propargyl,
--C.sub.6 H.sub.4 CN or --C.sub.6 H.sub.4 CH.sub.2 CN, --C.sub.6
H.sub.4 C.tbd.CH, --C.sub.6 H.sub.4 OH,.
12. The process of claim 11 wherein the phenol is m-cresol or a
mixture of m-cresol and its isomers and the organic azeotroping
agent is a cyclic hydrocarbon of 6 to 8 carbon atoms.
13. The process of claim 1 wherein (1) the tetracarboxylic acid
dianhydride is selected from the group consisting of
3,3',4,4'-benzophenonetetracarboxylic acid dianhydride,
pyromellitic anhydride and 1,4,5,8-naphthalenetetracarboxylic acid
dianhydride, (2) the aromatic diamine is selected from the group
consisting of m-phenylenediamine, p-phenylenediamine,
4,4'-oxydianiline, 3,3'-sulfonyldianiline,
4,4'-diaminobenzophenone, 4,4'-methylenedianiline and
4,4'-diaminostilbene, (3) R"NH.sub.2 is selected from the group
consisting of styryl amine, amino phenyl acetylene, p-aminophenol,
allyl amine, propargyl amine, aminobenzonitrile and aminobenzyl
cyanide, (4) the phenol is m-cresol or mixtures of m-cresol and its
isomers and (5) the organic azeotroping agent is a cyclic
hydrocarbon of 6 to 8 carbon atoms.
14. The process of claim 13 wherein the cyclic hydrocarbon is an
aromatic hydrocarbon.
15. The process of claim 14 wherein n is at least 4 and the
aromatic hydrocarbon is benzene.
16. The process of claim 13 wherein the cyclic hydrocarbon is
subsequently removed.
17. The process of claim 1 wherein the azeotroping agent is
subsequently removed.
18. An end-capped polyimide having the structural formula:
##STR29## wherein Ar is a divalent aromatic organic radical,
Ar' is a tetravalent aromatic organic radical, the four carbonyl
groups being attached directly to separate carbon atoms and each
pair of carbonyl groups being attached to adjacent carbon atoms in
the Ar' radical,
R" is allyl, styryl, ##STR30## --C.sub.6 H.sub. 4 CN or --C.sub.6
H.sub.4 CH.sub.2 CN, and n is a positive integer of at least 4.
19. The polyimide of claim 18 wherein Ar' is a tetravalent radical
containing at least one ring of six carbon atoms, said ring
characterized by benzenoid unsaturation.
20. The polyimide of claim 19 wherein Ar is a divalent benzenoid
radical selected from the group consisting of ##STR31## and
multiples thereof connected to each other by R.sup.IV wherein
R.sup.IV is selected from the group consisting of --CH=CH--, an
alkylene chain of 1-3 carbon atoms, ##STR32## wherein R.sup.V and
R.sup.VI are selected from the group consisting of alkyl of 1 to 6
carbon atoms or aryl of 6 carbon atoms.
21. A substantially cyclized polyimide soluble in phenols having
the formula: ##STR33## wherein Ar is a divalent aromatic organic
radical,
Ar' is a tetravalent aromatic organic radical, the four carbonyl
groups being attached directly to separate carbon atoms and each
pair of carbonyl groups being attached to adjacent carbon atoms in
the Ar' radical, ##STR34## R" is a hydrocarbon radical of 1 to 12
carbon atoms which is saturated, has olefinic unsaturation and
--OH, --CN, --CHO or --CH=NR" substituted derivatives thereof,
and
n has a numerical value of 4 to 100.
22. The polyiminde of claim 21 in which the phenol is selected from
the class of phenol, cresols and xylenols and mixtures thereof.
Description
BACKGROUND OF THE INVENTION
1. Field of Invention
This invention relates to processes for preparing polyimides and to
certain novel polyimides and more particularly to processes for
preparing polyimides which are soluble in phenolic solvents.
2. Prior Art
The prior art is replete with references teaching the preparation
of polyimides and polyimide precursors by the reaction of aromatic
tetracarboxylic acids, or anhydrides thereof, with aromatic
diamines. While the polyimide articles formed have excellent heat
resistance, it is difficult to form articles because of their
insolubility and intractability. This has necessitated the use of
polyimide precursors which can be shaped into the desired form and
then cured to the polyimides. However, a difficulty with the
precursors is their release of by-products during curing which can
result in powdering and formation of voids in the article or the
use of polyimides having lower thermal stability. To minimize or
avoid these problems, thin layers must be used, especially in wire
enameling, and the desired thickness built up by applying numerous
layers. Thus, there is a continuing need in the art for thermally
stable polyimides that can cure in thick sections without the
aforementioned difficulties.
References illustrative of the state of the art are U.S. Pat. No.
3,277,043, issued Oct. 4, 1966 to Fred F. Holub, U.S. Pat. No.
3,678,015, issued to Fred F. Holub et al. and U.S. Pat. No.
3,666,709, issued May 30, 1972 to Munchiko Suzuki et al. The former
teaches a process for preparing phenolic solvent soluble polymers
by the reaction of an anhydride and diamine in a phenol under
initially substantially anhydrous conditions. The latter teaches a
phenolic solvent soluble polyimide by reacting an aromatic
tetracarboxylic acid and a diamine in a phenolic solvent at a
temperature above the boiling point of water. The second patent
shows a process for preparing a polyimide precursor by reacting a
diamine and an aliphatically unsaturated hydrocarbon monoanhydride
(with up to 10% dianhydride) in the presence of an inert
hydrocarbon solvent and an inert phenolic solvent.
SUMMARY OF THE INVENTION
According to the present invention there is provided a process for
the preparation of a substantially cyclized polyimide of the
formula: ##STR1## wherein
Ar is a divalent aromatic organic radical,
Ar' is a tetravalent aromatic organic radical, the four carbonyl
groups being attached directly to separate carbon atoms and each
pair of carbonyl groups being attached to adjacent carbon atoms in
the Ar' radical, ##STR2## or HOOC-R'"--CONH-- where R" and R'" are
defined hereinafter, ##STR3## where R" and R"' are defined
hereinafter, and n is 0 or a positive integer of at least one,
soluble in an aromatic phenol which comprises:
1. reacting a reaction mixture of at least one tetracarboxylic acid
dianhydride of the formula: ##STR4## wherein Ar' is as defined
above, and at least one aromatic diamine of the formula:
wherein Ar is as defined above, at a molar ratio of dianhydride to
diamine in the range of m to m + 1: m to m+ 1 where m is a positive
integer of at least one and as high as n in formula (A), with the
proviso that when the ratio of dianhydride to diamine is m + 1: m,
the reaction mixture contains 0 or 2 moles of a monoamine of the
formula R"NH.sub.2 wherein R" is a hydrocarbon radical of 1 to 12
carbon atoms which is saturated, has olefinic unsaturation or
acetylenic unsaturation, and --CN, --CHO or --CH=NR" substituted
derivatives thereof, and when the ratio of dianhydride to diamine
is m:m + 1, the reaction mixture contains 0 or 2 moles of an
.alpha.,.beta.-carboxylic acid monoanhydride of the formula
##STR5## where R'" is a hydrocarbon radical of 2 to 12 carbon atoms
which is saturated, has olefinic unsaturation or benzenoid
unsaturation, in an aromatic phenol of the formula where each R' is
hydrogen or --CH.sub.3 is the presence of at least one organic
azeotroping agent which:
a. gives a water azeotrope having a boiling point less than
95.degree. C. at atmospheric pressure,
b. is non-reactive with the dianhydride and the diamine, and
c. separates from water as a distinct phase, said reaction
conducted at a temperature less than 140.degree. C. and below the
boiling point of said aromatic phenol and higher than the boiling
point of said azeotroping agent with the vapor phase temperature
being between that of the water azeotrope and no higher than
95.degree. C.
2. removing water of reaction and the azeotroping agent from the
reaction mixture as a water azeotrope and
3. returning quantities of azeotroping agent to the reaction
mixture to maintain the temperature and reaction mixture volume
substantially constant.
There is also provided a self-crosslinking polyimide having the
structural formula: ##STR6## wherein
Ar is a divalent aromatic organic radical, and
n is a positive integer of at least 4.
There is further provided an end-capped polyimide having the
structural formula: ##STR7## wherein
Ar, Ar' and R" are as define previously and
n is at least 4.
DETAILED DESCRIPTION OF THE INVENTION
The process of the present invention uses as starting materials an
aromatic dianhydride, an aromatic diamine, an aromatic phenol
solvent and an organic azeotroping agent. Optional materials are a
monoamine and an .alpha.,.beta.-carboxylic acid monoanhydride. The
aromatic dianhydride has the general formula: ##STR8## wherein Ar'
is a tetravalent aromatic organic radical, preferably containing at
least one ring of six carbon atoms, said ring characterized by
benzenoid unsaturation, the four carbonyl groups being attached
directly to separate carbon atoms and each pair of carbonyl groups
being attached to adjacent carbon atoms in the Ar' radical. Any of
the aromatic tetracarboxylic acid dianhydrides known in the prior
art can be used. Among the useful dianhydrides are 3,3',
4,4'-benzophenonetetracarboxylic acid dianhydride, pyromellitic
dianhydride, 2,3,6,7-naphthalene tetracarboxylic acid dianhydride,
3,3', 4,4'-diphenyl tetracarboxylic acid dianhydride,
1,2,5,6-naphthalene tetracarboxylic acid dianhydride, 2,2',
3,3'-diphenyl tetracarboxylic acid dianhydride,
2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 3,4,9,10-perylene
tetracarboxylic acid dianhydride, bis(3,4-dicarboxyphenyl)ether
dianhydride, naphthalene-1,2,4,5-tetracarboxylic acid dianhydride,
naphthalene-1,4,5,8-tetracarboxylic acid dianhydride,
decahydronaphthalene-1,4,5,8-tetracarboxylic acid dianhydride,
4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1,2,5,6-tetracarboxylic
acid dianhydride, 2,6-dichloronaphthalene-1,4,5,8-tetracarboxylic
acid dianhydride, 2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic
acid dianhydride,
2,3,6,7-tetrachloronaphthalene-1,4,5,8-tetracarboxylic acid
dianhydride, phenanthrene-1,8,9,10-tetracarboxylic acid
dianhydride, cyclopentane-1,2,3,4-tetracarboxylic acid dianhydride,
pyrrolidine-2,3,4,5-tetracarboxylic acid dianhydride,
pyrazine-2,3,5,6-tetracarboxylic acid dianhydride,
2,2-bis(2,3-dicarboxyphenyl)propane dianhydride,
1,1-bis-(2,3-dicarboxyphenyl)ethane dianhydride,
1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride,
bis(2,3-dicarboxyphenyl)methane dianhydride,
bis(3,4-dicarboxyphenyl)methane dianhydride,
bis(3,4-dicarboxyphenyl)sulfone dianhydride,
benzene-1,2,3,4-tetracarboxylic acid dianhydride and
thiophene-2,3,4,5-tetracarboxylic acid dianhydride and the like.
Preferred dianhydrides are 3,3', 4,4'-benzophenonetetracarboxylic
dianhydride, pyromellitic anhydride and
1,4,5,8-naphthalene-tetracarboxylic and dianhydride with the first
one most preferred.
Aromatic diamines useful in the present process have the general
formula:
wherein Ar is a divalent aromatic organic radical. Preferred
aromatic diamines are those wherein Ar is a divalent benzenoid
radical selected from the group consisting of ##STR9## and
multiples thereof connected to each other by R.sup.IV, e.g.,
##STR10## wherein R.sup.IV represents --CH=CH--, an alkylene chain
of 1-3 carbon atoms, ##STR11## wherein R.sup.V and R.sup.VI are
each selected from the group consisting of alkyl and aryl
containing one to six carbon atoms, e.g., methyl, ethyl, propyl,
hexyl, n-butyl, and i-butyl.
Examples of aromatic diamines which are suitable for use in the
present invention are 4,4'-diaminodiphenyl propane,
4,4'-diamino-diphenyl methane, benzidine, 3,3'-dichlorobenzidine,
4,4'-diamino-diphenyl sulfide, 4,4'-diaminostilbene,
3,3'-diamino-diphenyl sulfone, 4,4'-diamino-diphenyl sulfone,
4,4'-diamino-diphenyl ether, 1,5-diamino naphthalene,
4,4'-diamino-diphenyl diethylsilane, 4,4'-diamino-diphenyl
diphenylsilane, 4,4'-diamino-diphenyl ethyl phosphine oxide,
4,4'-diamino-diphenyl phenyl phosphine oxide, 4,4'-diamino-diphenyl
N-methyl amine, 4,4'-diamino-diphenyl N-phenyl amine and mixtures
thereof. 3,3'-dimethyl-4,4'-diaminodiphenylmethane,
3,3'-diethyl-4,4'-diaminodiphenylmethane,
3,3'-dimethoxy-4,4'-diaminodiphenylmethane,
3,3'-diethoxy-4,4'-diaminodiphenylmethane, 3,3'-dichloro-4,4',
4,4'-diaminodiphenylmethane,
3,3'-dibromo-4,4'-diaminodiphenylmethane,
3,3'-dicarboxy-4,4'-diaminophenylmethane,
3,3'-dihydroxy-4,4'-diaminophenylmethane,
3,3'-disulpho-4,4'-diaminodiphenylmethane,
3,3'-dimethyl-4,4'-diaminodiphenylether,
3,3'-diethyl-4,4'-diaminodiphenylether,
3,3'-dimethoxy-4,4'-diaminodiphenylether,
3,3'-diethoxy-4,4'-diaminodiphenylether,
3,3'-dichloro-4,4'-diaminodiphenylether, 3,3'-dibromo-4,4'-diamino
diphenylether, 3,3'-dicarboxy-4,4'-diaminodiphenylether,
3,3'-dihydroxy-4,4'-diaminodiphenylether,
3,3'-disulfo-4,4'-diaminodiphenylether,
3,3'-dimethyl-4,4'-diaminodiphenylsulfide,
3,3'-diethyl-4,4'-diaminodiphenylsulfide,
3,3'-dimethoxy-4,4'-diaminodiphenylsulfide,
3,3'-diethoxy-4,4'-diaminodiphenylsulfide,
3,3'-dichloro-4,4'-diaminodiphenylsulfide,
3,3'-dibromo-4,4'-diaminodiphenylsulfide,
3,3'-dicarboxyl-4,4'-diaminodiphenylsulfide,
3,3'-dihydroxy-4,4'-diaminodiphenylsulfide,
3,3'-disulfo-4,4'-diaminodiphenylsulfide,
3,3'-dimethyl-4,4'-diaminodiphenylsulfone,
3,3'-diethoxy-4,4'-diaminodiphenylsulfone,
3,3'-dichloro-4,4'-diaminodiphenylsulfone,
3,3'-dicarboxy-4,4'-diaminodiphenylsulfone,
3,3'-dihydroxy-4,4'-diaminodiphenylsulfone,
3,3'-disulfo-4,4'-diaminodiphenylsulfone, 3,3'
-diethyl-4,4'-diaminodiphenylpropane,
3,3'-dimethoxy-4,4'-diaminodiphenylpropane,
3,3'-dibromo-4,4'-diaminodiphenylpropane,
3,3'-dichloro-4,4'-diaminodiphenylpropane,
3,3'-dicarboxy-4,4'-diaminodiphenylpropane,
3,3'-dihydroxy-4,4'-diaminodiphenylpropane,
3,3'-disulfo-4,4'-diaminodiphenylpropane,
3,3'-dimethyl-4,4'-diaminobenzophenone,
3,3'-dimethoxy-4,4'-diaminobenzophenone,
3,3'-dichloro-4,4'-diaminobenzophenone,
3,3'-dibromo-4,4'-diaminobenzophenone,
3,3'-dicarboxy-4,4'-diaminobenzophenone,
3,3'-dihydroxy-4,4'-diaminobenzophenone,
3,3'-disulphodiaminobenzophenone, 3,3'-diaminodiphenylmethane,
3,3'-diaminodiphenylether, 3,3'-diaminodiphenylsulfide,
3,3'-diaminodiphenylsulfone, 3,3'-diaminodiphenylpropane,
3,3'-diaminobenzophenone, 2,4-diaminotoluene, 2,6-diaminotoluene,
1-isopropyl-2,4-phenylenediamine, 2,4-diaminoanisole,
2,4-diaminomonochlorobenzene, 2,4-diaminofluorobenzene,
2,4-diaminobenzoic acid, 2,4-diaminophenol, and
2,4-diaminobenzenesulfonic acid, and phenylene diamines. Preferred
diamines are m-phenylenediamine, p-phenylenediamine,
4,4'-oxydianiline, 3,3'-sulfonyldianiline,
4,4'-diaminobenzophenone, 4,4'-methylenedianiline and
4,4'-diaminostilbene.
The aromatic phenols useful as solvents have the formula ##STR12##
where each R' is hydrogen or a methyl radical. These phenols
include phenol, the various cresol isomers such as o-, m-, and
p-cresol, and the various xylenols such as 2,3-xylenol,
2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol and 3,5-xylenol.
Of these, the cresols are preferred. In particular, pure m-cresol
or a mixture of m-cresol and the other isomers is especially
preferred because of commercial availability and its ease of
recovery. The ratio of phenol solvent to dianhydride and diamine
can be varied over a wide range depending on the nature of the
reactants. Usually, enough solvent is used to dissolve the
reactants.
Any organic compound can be used as the azeotroping agent to remove
water formed during the reaction provided it (a) gives a water
azeotrope having a boiling point less than 95.degree. C. at
atmospheric pressure, preferably less than 90.degree. C., (b) is
non-reactive with the dianhydride and the diamine and (c) separates
from water as a distinct phase when condensed so that the agent can
be returned to the reaction mixture to maintain the temperature of
reaction and the reaction mixture volume substantially constant
(only water is depleted). The organic compound should also be
soluble in the phenolic solvent. Examples of such azeotroping
agents and their azeotrope boiling points with water are as
follows:
______________________________________ Agent Azeotrope B.P.
.degree. C. ______________________________________ Benzene 69.4
Butyl chloride 68.0 Butyl ether 94.1 Butyronitrile 88.7 Carbon
tetrachloride 66.8 Chloroform 56.3 Cyclohexane 69.8 1-Butenylmethyl
ether-cis 64.0 1-Butenylmethyl ether-trans 67.0 Butyl acetate 90.7
Ethyl acetate 70.4 Ethyl benzene 92.0 Ethylbutyl ether 76.6
Ethylenedichloride 71.6 Heptane 79.2 Hexane 61.6 Isopropyl ether
62.2 Methyl acetate 56.1 Octane 89.6 Propionitrile 82.2 Propyl
acetate 82.4 Tetrachloroethylene 88.5 Toluene 85.0
1,1,2-Trichloroethane 86.0 m-Xylene 94.5
______________________________________
Ternary systems can also be used. Illustrative ternary systems and
their azeotrope boiling points with water are:
______________________________________ Agents Azeotrope B.P.
.degree. C. ______________________________________
Acetonitrile/Benzene 66.0 Acetonitrile/Isopropyl ether 59.0
Acetonitrile/Trichloroethylene 67.0
______________________________________
Preferred azeotroping agents are the cyclic hydrocarbons of 6 to 8
carbon atoms, with the aromatic hydrocarbons particularly
preferred. While benzene is preferred because of its low boiling
point, toluene is also preferred because of its lower toxicity.
Saturated cyclic hydrocarbons such as cyclohexane, cyclooctane and
the like can also be used but they are not as preferred as the
aromatic hydrocarbons.
The optional materials which can be present in the reaction mixture
are a monoamine and an .alpha.,.beta.-carboxylic acid
monoanhydride. When the optional materials are not used, the
polyimides prepared by the present process either have two
anhydride end groups (when the molar ratio of dianhydride to
diamine is m + 1: m), two amine end groups (when the molar ratio of
dianhydride to diamine is m:m + 1) or one anhydride end group and
one amine end group (when the molar ratio of dianhydride to diamine
is m:m ). When the optional materials are used, two moles are used
to end-cap the polyimide. Thus, when the molar ratio of dianhydride
to diamine is m + 1: m, two moles of the monoamine R"NH.sub.2 can
be added to the reaction mixture and when the molar ratio is m:m +
1, two moles of the .alpha.,.beta.-carboxylic acid monoanhydride
can be added to the reaction mixture.
The monoamine used has the formula R"NH.sub.2 wherein R" is a
hydrocarbon radical of 1 to 12 carbon atoms which is saturated, has
olefinic unsaturation or acetylenic unsaturation, e.g., aliphatics
such as alkyl, alkylene and alkyne, cycloaliphatics such as
cycloalkyl and cycloalkylene, aromatics such as aryl, alkaryl,
aralkyl. Also included are the --CN, --CHO and --CH=NR" derivatives
of the hydrocarbon radicals. Examples of R" are --CH.sub.3,
--C.sub.2 H.sub.5, --C.sub.3 H.sub.7, --C.sub.8 H.sub.17,
--CH=CH.sub.2, --CH.sub.2 CH=CH.sub.2, --CH.sub.2 CH=CHCH.sub.3,
--CH=CHCH.sub.3, --C.tbd.CH, --C.tbd.CCH.sub.3, --CH.sub.2
C.tbd.CH, --CH=CHCH=CH.sub.2, --C.sub.6 H.sub.11 (cyclohexane),
--C.sub.6 H.sub.9 (cyclohexene), --C.sub.5 H.sub.9 (cyclopentane),
--C.sub.5 H.sub.7 (cyclopentene), --C.sub.6 H.sub.5 (phenyl),
--C.sub.6 H.sub.4 CH.sub.3, --C.sub.6 H.sub.3 (CH.sub.3).sub.2,
--C.sub. 6 H.sub.5 C.sub.2 H.sub.5, --C.sub.10 H.sub.7 (naphthyl),
--C.sub.10 H.sub.6 CH.sub.3, --C.sub.10 H.sub.5 (CH.sub.3).sub.2,
--CH.sub.2 C.sub.6 H.sub.5, --CH.sub.2 C.sub.6 H.sub.4 CH.sub.3,
--C.sub.6 H.sub.4 CH=CH.sub.2, ##STR13## --CH.sub.2 C.sub.6 H.sub.4
CH=CH.sub.2, --C.sub.6 H.sub.4 CH.sub.2 CH=CH.sub.2, --C.sub.6
H.sub.4 C.tbd.CH, --C.sub.6 H.sub.4 C.tbd.CCH.sub.3 and --C.sub.6
H.sub.4 CH.sub.2 C.tbd.CCH.sub.3.
Examples of --CN, --CHO and --CH=NR" derivatives thereof are
--CH.sub.2 CN, --CH.sub.2 CH=CHCN, --CH.sub.2 C.tbd.CCN, --C.sub.6
H.sub.4 CN, --C.sub.6 H.sub.3 (CH.sub.3)CN, --C.sub.6 H.sub.4
CH.sub.2 CN, --CH.sub.2 C.sub.6 H.sub.4 CN, --C.sub.6 H.sub.4 CN,
--C.sub.6 H.sub.4 CH=CHCN, --C.sub.10 H.sub.7 CN, --C.sub.6 H.sub.3
(CN).sub.2, --CH.sub.2 C.sub.6 H.sub.4 CH.sub.2 CN, --C.sub.6
H.sub.4 CHO, --C.sub.6 H.sub.4 CH.sub.2 CHO, --CH.sub.2 C.sub.6
H.sub.4 CH.sub.2 CHO, --CH.sub.2 C.sub.6 H.sub.4 CHO, --C.sub.6
H.sub.4 CH=CHCHO, --C.sub.6 H.sub.4 CH=NC.sub.6 H.sub.5, --C.sub.6
H.sub.4 CH.sub.2 CH=NC.sub.6 H.sub.4 CH.sub.3 and the like.
Preferred monoamines are allyl amine, styryl amine, propargyl
amine, aminobenzyl cyanide, and aminobenzyl nitrile with allyl
amine, styryl amine and propargyl amine particularly preferred.
The .alpha.,.beta.-carboxylic acid monoanhydride used has the
formula ##STR14## wherein R'" is a hydrocarbon radical of 2 to 12
carbon atoms which is saturated, has olefinic unsaturation or
benzenoid unsaturation. Examples of such monoanhydrides are
##STR15## The terms .alpha.,.beta. in the expression
.alpha.,.beta.-monocarboxylic monoanhydride has reference to the
position of substitution of the two carbonyl groups in the
anhydride, and is equivalent to a 1,2 substitution on adjacent
carbon atoms; in the benzenoid series this substitution is referred
to as ortho substitution. The preferred monoanhydrides are maleic
anhydride and phthalic anhydride.
When maleic anhydride is used as the monoanhydride, cyclization is
easily accomplished by removing the azeotroping agent from the
reaction mixture and then adding a lower aliphatic acid anhydride
such as acetic acid and an alkali metal salt of a lower aliphatic
acid such as sodium or potassium acetate.
In carrying out the process of the invention, a reaction mixture of
at least one dianhydride, at least one diamine and optionally the
monoamine or monoanhydride, in at least one aromatic phenol solvent
is reacted in the presence of the organic azeotroping agent until
substantially all of the water of reaction is eliminated. The
reaction temperature is less than 140.degree. C. and also should be
below the boiling point of the aromatic phenol used but higher than
the boiling point of the azeotroping agent. The vapor phase
temperature lies between that of the water azeotrope and no higher
than 95.degree. C. As the water of reaction and azeotroping agent
are removed from the reaction mixture, quantities of the
azeotroping agent are returned to the reaction mixture so as to
maintain the temperature and reaction mixture volume substantially
constant. It is preferred that the process be continuous with
continuous removal of water and continuous return of azeotroping
agent. This is conveniently done by the use of a conventional
deanstark trap and condenser wherein after the azeotrope condenses,
the water preferably sinks to the bottom of the trap for subsequent
removal and the azeotroping agent overflows the trap and returns to
the reaction mixture. Initially, the trap is filled with
azeotroping agent.
The present azeotroping process with a return of the azeotroping
agent is unique in that it prepares a substantially completely
cyclized polyimide at low temperatures which is soluble in phenolic
solvent. Time of reaction is generally less than 1 hour (usually
30-45 minutes) with a substantially quantitative yield of the
polyimide in solution.
After the water of reaction is eliminated, the azeotroping agent is
usually removed so that the solution of polyimide in aromatic
phenol can either be directly used as a coating composition or
adhesive or further treated before the polyimide is used. Further
treatment of the solution can involve precipitation of the
polyimide as a powder which can then be used in end-use
applications. Also, the solution can be bodied, i.e., the polyimide
increased in molecular weight by heating the solution with periodic
removal of some of the phenolic solvent. Further, the polyimides
can be further reacted to higher molecular weight polymers as
described in my copending application Ser. No. 363,801, filed even
date herewith.
Many of the polyimides prepared are novel polymeric materials. For
example, when 3,3',4,4'-benzophenone-tetracarboxylic acid
dianhydride is used as the dianhydride and the molar ratio of
dianhydride to diamine is m:m + 1, a self-crosslinking polyimide is
prepared. It has the structural formula: ##STR16## wherein
Ar is a divalent aromatic organic radical, and
n is a positive integer of at least 4.
Also, many of the end-capped polyimides are novel. For example,
when the molar ratio of dianhydride to diamine is m + 1:m and 2
moles of the preferred monoamine are used, an end-capped polyimide
is prepared having the structural formula: ##STR17## wherein
Ar and Ar' are as defined above,
R" is allyl, styryl, propargyl, --C.sub.6 H.sub.4 CN
or --C.sub.6 H.sub.4 CH.sub.2 CN, and
n is a positive integer of at least 4. The polyimides described
above in (A) and (B) wherein n is at least 4 have a polyimide
character which gives them good thermal stability, especially when
cured by cross-linking (A) or post-reacting (B) as described in my
aforementioned copending application Ser. No. 363,801.
In general, however, many substantially cyclized polyimides can be
prepared by the process of the invention. They can either be
monomeric, oligomeric or polymeric with the degree of repeating
units being dependent to some extent on the molar ratio of
dianhydride to diamine used. The polyimides prepared will have the
structural formula: ##STR18## When the ratio is 1:1, the core of
the polyimide will generally provide an n of about 10-12 units and
when the ratio is about 1.1:1, n will be about 6 or 7 units.
However, the number of units n can be as high as 500 to 1,000 or
greater. Usually n will be in the range of about 1 to 100,
preferably 4 to 15. The process of the invention enables the
skilled artisan to control molecular weight through bodying and the
reactivity of polymerization.
The soluble polyimides prepared by the present process have a
number of uses. These include use of the solutions as wire and
insulating varnishes and to impregnate fabric substrates used in
making flexible and rigid electronic circuit boards and in making
structural laminates. The solutions can be used to make fibers and
films and as adhesives, particularly for film substrates, useful in
aerospace and electronics applications. The powders can be used as
molding powders and to make fibers and films.
The invention can be further understood by the following examples
in which parts and percentages are by weight unless otherwise
indicated.
EXAMPLE 1
Preparation of Aromatic Nitrile-Terminated Oligomeric Polyimide
(BTAN-2). Reaction of 3,3',4,4'-Benzophenone- tetracarboxylic Acid
Dianhydride (BTCA), 4,4'-Oxydianiline (ODA) and 4-Aminobenzonitrile
(AN) (2:1:1).
An apparatus consisting of a 100-ml. three-neck, round-bottom flask
equipped with a magnetic stirrer, Dean-Stark trap and condenser, a
dropping funnel, heating mantle, etc. is used in this and numerous
following syntheses. For purposes of brevity, it will be called the
"m-cresol: benzene azeotropic apparatus."
In the m-cresol:benzene azeotropic apparatus there was placed a
solution of 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride
(BTCA) (3.222 g., 0.01 mole) in 25 ml. m-cresol and 15 ml. benzene.
The mixture was warmed to approximately 50.degree. C. and a
solution of 4,4'-oxydianiline (ODA) (1.001 g., 0.005 mole) in 15
ml. of m-cresol was added, giving an immediate yellow precipitate.
After 15 minutes, a solution of 4-aminobenzonitrile (AN) (1.299 g.,
0.011 mole) in 10 ml. of m-cresol was added. During 2 hours of
refluxing, the solution became orange and 0.25 ml of water was
collected. Precipitation did not occur. After cooling, the solvents
were removed on a rotary flash evaporator and the residue was
vacuum-dried at 100.degree. C. to yield 5.177 g. (102%) of
phenylnitrile-terminated oligomeric polyimide based on BTCA
(BTAN-2). On a Fisher-Johns melting point apparatus, 230.degree. C.
was the lowest temperature at which it softened before rehardening
immediately. It was soluble in hot m-cresol, slightly soluble in
hot dimethyl acetamide (DMAC), and insoluble in hot acetone. A
sample of BTAN-2 was postheated in nitrogen at 300.degree. C. for
24 hours, and its TGA in nitrogen of sample BTAN-2-H300, showed an
inflection point at 410.degree. C.
Analysis: Calc'd. for C.sub.60 H.sub.28 N.sub.6 O.sub.11 :
C, 71.43; H, 2.80; N, 8.03; O, 17.44,
Found: C, 70.83; H, 2.81; N, 7.77; O, - - - .
Found: C, 71.22; H, 2.86; N, 7.93; O, - - -
(dried at 140.degree. C.).
When other dianhydrides of ##STR19## are used in equivalent amounts
in this example instead of BTCA, the corresponding completely
cyclized, nitrile terminated diimide is obtained. Similarly, when
other amines R"NH.sub.2, e.g., NH.sub.2 C.sub.6 H.sub.4
CH=CH.sub.2, NH.sub.2 CH=CH.sub.2 CH.sub.2, NH.sub.2 CH.sub.2
C.tbd.CH, NH.sub.2 C.sub.6 H.sub.5 CHO, and NH.sub.2 C.sub.6
H.sub.5 CH=NC.sub.6 H.sub.5 are used in equivalent amounts in this
example instead of AN with BTCA or the other dianhydrides, the
corresponding amine terminated diimides are obtained.
EXAMPLE 2
Preparation of Aromatic Nitrile-Terminated Oligomeric Polyimide
(BTAN-3). Reaction of BTCA, 3,3'-Sulfonyldianiline (SDA-3,3) and AN
(9:8:2).
In a m-cresol: benzene azeotropic apparatus there was placed a
solution of BTCA; (2.1750 g., 0.00675 mole) in 25 ml. of m-cresol
and 10 ml. of benzene. The solution was warmed to approximately
70.degree. C. and a solution of AN (0.1773 g., 0.0015 mole) in 10
m-cresol was added over about 20 minutes. After stirring at
approximately 70.degree. C. for 15 minutes, a solution of
3,3'-sulfonyldianiline (SDA-3,3) (1,4899 g., 0.0060 mole) in 15 ml.
of m-cresol was added and the solution was heated to reflux for 3
hours, during which time, 0.3 ml. of water was collected; then the
benzene was distilled off and after cooling to room temperature,
the solution was added dropwise slowly to 200 ml. of well-stirred
methanol, to yield a light-yellow solid. The solid was filtered
off, digested four times in hot methanol, and dried at 40.degree.
C. for 24 hours, to give 3.40 g. (95%) of yellow product. The
yield, corrected for about 2% retained m-cresol, was 93.5%. The
oligomer partially melted at 255.degree. C. and rehardened at
275.degree. C.; it was soluble in m-cresol, DMAC and hot sulfolane,
but insoluble in dioxane. A small sample, vacuum-dried at
200.degree. C. for 4 hours, showed a 2% loss of m-cresol, which was
confirmed in its TGA in nitrogen, which also shows an inflection
point in nitrogen in the 500.degree. C. region. Its DTA in nitrogen
shows an endotherm at 225.degree. C.
Analysis: Calc'd. for C.sub.263 H.sub.126 N.sub.20 O.sub.61 S.sub.8
:
C, 65.83; H, 2.65; N, 5.84; O, 20.34; S, 5.35.
Found: C, 65.29; H, 2.70; N, 5.36; O, - - - ; S, - - - .
The above procedure was repeated except that the quantities used
were increased to yield 33.0 g. (97%) of BTAN-3. The quantities
used were BTCA, 21.7505 g., 0.0675 mole; SDA-3,3, 14.899 g., 0.060
mole; AN, 1.7172 g., 0.0150 mole.
When other dianhydrides of ##STR20## are used in equivalent amounts
in this example instead of BTCA, the corresponding completely
cyclized, nitrile terminated diimide is obtained. Similarly, when
other amines R"NH.sub.2, e.g., NH.sub.2 C.sub.6 H.sub.4
CH=CH.sub.2, NH.sub.2 CH.sub.2 CH=CH.sub.2, NH.sub.2 CH.sub.2
C.tbd.CH, NH.sub.2 C.sub.6 H.sub.5 CHO, and NH.sub.2 C.sub.6
H.sub.5 CH=NC.sub.6 H.sub.5 are used in equivalent amounts in this
example instead of AN with BTCA or the other dianhydrides, the
corresponding amine terminated diimides are obtained.
EXAMPLE 3
Preparation of Aromatic Nitrile-Terminated Oligomeric Polyimide
(BTAN-4). Reaction of BTCA, 1,3Di(3-Aminophenoxy)benzene (DAPB-3,3)
and AN (9:8:2).
In a m-cresol:benzene azeotropic apparatus there was placed a
solution of BTCA (2.1753 g., 0.00675 mole) in 25 ml. of m-cresol
and 10 ml of benzene. The solution was warmed to approximately
70.degree. C. and a solution of AN (0.1773 g. 0.0015 mole) in 10
ml. of m-cresol was added over about 20 minutes. After stirring for
another 15 minutes, a solution of 1,3-di(3-aminophenoxy)benzene
(DAPB-3,3) (1.7540 g., 0.0060 mole) in 15 ml of m-cresol was added.
The solution was heated to reflux for 3 hours and 0.2 ml of water
was collected. Then the benzene was distilled off. After cooling,
the clear solution was added dropwise to 200 ml of methanol. The
precipitated solid was digested three times in hot methanol and
vacuum-dried at 70.degree. C. to give BTAN-4, as a light-yellow
solid, 3.4 g. (88%).
The infrared spectrum (KBr disc) of BTAN-4 is given in FIG. 29; it
was soluble in m-cresol, DMAC, sulfolane, dioxane; because a paste
in methylene chlordie, swelled in chloroform and was insoluble in
acetonitrile. BTAN-4 softened at 180.degree. C., melted over the
range of 197-218.degree. C., thickened above 290.degree. C., but
did not harden within 20 minutes at 300.degree. C., although it did
darken somewhat. For the sample dried at 70.degree. C., the DTA in
nitrogen showed a melting endotherm at about 180.degree. C.
A sample of BTAN-4, vacuum-dried at 200.degree. C., to eliminate
volatiles, was submitted for analysis.
Analysis: Calc'd. for C.sub.305 H.sub.158 N.sub.20 O.sub.61 :
C, 72.13; H, 3.14; N, 5.52; O, 19.22
Found: C, 72.41; H, 3.28; N, 5.11; O, - - - .
EXAMPLE 4
Synthesis of Allyl-Terminated Oligomeric Polyimide (BTAA-3).
Reaction of BTCA, ODA and Allylamine (2:1:2).
In a m-cresol:benzene azeotropic apparatus, there was placed a
solution of BTCA (3.222 g., 0.01 mole) in 25 ml. of m-cresol and 15
ml. of benzene. The solution was warmed to approximately 60.degree.
C. and a solution of ODA (1.001 g., 0.005 mole) in 15 ml. of
m-cresol was added, forming an immediate yellow precipitate which
dissolved on heating further for 5 minutes. Then, a solution of
allylamine (0.629 g., 0.011 mole) in 10 ml of m-cresol was added,
after which the solution was heated to reflux; during 2 hours of
reflux 0.25 ml. of water was collected. After cooling, the solution
was made up to 80 ml. with added benzene, and it was divided into
two 40-ml. portions.
The first 40-ml. fraction was added to 250 ml. of methanol and then
stirred for 1 hour. This solid material was isolated by
centrifuging and dried in a vacuum oven at 80.degree. C. for 36
hours, yielding a yellow solid (A), 1.87 g. (84%).
The second 40-ml. fraction was evaporated on a rotary flash
evaporator and the residue was dried in a vacuum oven at 80.degree.
C., yielding a yellow solid (B), 2.306 g. (104%). Sample B softened
at 130.degree. C., was nearly completely molten at 200-300.degree.
C., darkened in 10 minutes at 230.degree. C., was soluble in hot
m-cresol, slightly soluble in hot DMAC, and insoluble in
acetone.
Analysis: Calc'd. for C.sub.52 H.sub.30 N.sub.4 O.sub.11 :
C, 70.42; H, 3.41; N, 6.32; O, 19.85.
Found: C, 70.99; H, 3.79; N, 6.47; O, - - - .
A sample of BTAA-3B was postheated in nitrogen at 300.degree. C.
for 24 hours, and its TGA in nitrogen, at 10.degree. C./minute,
showed an inflection point at 360.degree. C.
EXAMPLE 5
Preparation of Aliphatic Nitrile-Terminated Oligomeric Polyimide
(BTBN-1). Reaction of BTCA, ODA and 4-Aminobenzyl Cyanide (BN)
(2:1:2).
In a m-cresol:benzene azeotropic apparatus was placed a solution of
BTCA (3.222 g., 0.01 mole) in 25 ml. m-cresol and 15 ml of benzene.
The mixture was warmed to approximately 50.degree. C. and a
solution of ODA (1.001 g., 0.005 mole) in 15 ml. of m-cresol was
added, giving an immediate yellow precipitate. After refluxing for
15 minutes, a solution of aminobenzyl cyanide (BN) (1.454 g., 0.011
mole) in 10 ml. of m-cresol was added. The precipitate dissolved
quickly. During 11/2 hours of reflux, 0.30 ml. of water was
collected and a precipitate formed. Then sodium acetate (0.041 g.,
0.0005 mole) was added and reflux was continued for another hour,
and another 0.05 ml. of water was collected. After cooling, the
solvents were removed on a rotary flash evaporator and the residue
was dried in a vacuum oven at 100.degree. C., the yield was 5.170
g. (.about.100%). Its infrared spectrum was consistent with the
expected structure. Benzylcyanide-terminated oligomeric polyimide
based on BTCA (BTBN-1) softened at 200.degree. C., was almost
completely melted by 290.degree. C. and rehardened rapidly at
300.degree. C. Also, it was soluble in hot m-cresol, slightly
soluble in hot DMAC, and insoluble in acetone. A sample dried at
300.degree. C. was also submitted for analysis.
Analysis: Calc'd. for C.sub.62 H.sub.32 N.sub.6 O.sub.11 :
C, 71.81; H, 3.11; N, 8.11; O, 16.97.
Found (B): C, 70.28; H, 3.22; N, 8.12; O, - - - .
dried at 300.degree. C.)
The TGA in nitrogen on the sample dried at 300.degree. C. showed an
inflection point of 360.degree. C.
EXAMPLE 6
Preparation of Aliphatic Nitrile-Terminated Oligomeric Polyimide
(BTBN-2). Reaction of BTCA, ODA and BN (2:1:2) using Inverse Order
of Addition.
In the m-cresol:benzene azeotropic apparatus was placed a solution
of BTCA (3.222 g. 0.01 mole) in 25 ml. of m-cresol and 10 ml. of
benzene. After warming to 50.degree. C., a solution of BN (1.3222
g., 0.01 mole) in 10 ml. of m-cresol was added. After 5 minutes, a
solution of ODA (1.001 g., 0.005 mole) in 15 ml. of m-cresol was
added and the reaction mixture heated to reflux. During 2 hours of
relux, 0.30 ml. of water was collected, a precipitate formed in the
reaction mixture. The solvents were removed on a rotary flash
evaporator and the residue was dried in a vacuum oven at
150.degree. C. to yield a yellow solid, 5.123 g. (99%). The product
softened at 60.degree. C., was partially melted by 260.degree. C.,
but rehardened at 265.degree. C. The infrared spectrum (KBr disc)
of BTBN-2 was substantially identical with that of BTBN-1 prepared
above. It was soluble in m-cresol and sulfolane but insoluble in
DMAC.
Analysis: Calc'd. for C.sub.62 H.sub.32 N.sub.6 O.sub.11 :
C, 71.81; H, 3.11.
Found: C, 70.99; H, 2.86.
EXAMPLE 7
Preparation of Aliphatic Nitrile-Terminated Oligomeric Polyimide
(BTBN-3). Reaction of BTCA, SDA-3,3 and BN (9:8:2).
According to the azeotropic procedure used in Example 2, BTCA
(2.1752 g., 0.00675 mole), BN (0.1982 g., 0.0015 mole) and SDA-3,3
(1.4898 g., 0.0060 mole) were allowed to react. There was obtained
3.27 g. (91%) of a light-yellow solid (BTBN-3). The yield,
corrected for approximately 1% retained m-cresol, was 89%.
The oligomer melted at 250-26.degree. C., and rehardened at
290.degree. C. It was soluble in m-cresol, DMAC and hot sulfonlane
but insoluble in dioxane.
A small portion, vacuum-dried at 200.degree. C. for 4 hours showed
a 1% loss of retained m-cresol, which was confirmed in its TGA in
nitrogen which also showed an inflection point in the 500.degree.
C. region.
The above procedure was repeated except that the quantities used
were such as to yield a larger amount of product: BTCA, 21.750 g.,
0.0675 mole; SDA-3,3, 14.899 g., 0.060 mole; BN, 1.982 g., 0.0150
mole. The BTBN-3 obtained from this reaction amounted to 34.8 g.
(96%).
Analysis: Calc'd. for C.sub.265 H.sub.130 N.sub.20 O.sub.61 S.sub.8
:
C, 65.94; H, 2.72; N, 5.80; O, 20.22; S, 5.32.
Found: C, 65.18; H, 2.65; N, 5.71; O, - - - ; S, - - - .
EXAMPLE 8
Preparation of Aliphatic Nitrile-Terminated Oligomeric Polyimide
(BTBN-4). Reaction of BTCA, DAPB-3,3 and BN (9:8:2).
According to the procedure used in Example 3 to prepare BTAN-4,
BTCA (2.1753 g., 0.00675 mole), BN (0.1982 g., 0.0015 mole) and
DAPB-3,3 (1.7540 g., 0.0060 mole) were allowed to react to afford,
after vacuum-drying at 70.degree. C., BTBN-4, 3.8 g. (97%) as a
light-yellow solid. BTBN-4 was soluble in m-cresol, DMAC, sulfolane
and dioxane. It was partially soluble in hot chloroform and hot
methylene chloride, and was insoluble in acetonitrile.
On a Fisher-Johns melting point apparatus, BTBN-4 softened at
135.degree. C., melted at 196-215.degree. C., thickened above
235.degree. C. and remelted at 255.degree. C. It did not reharden
when held for 1/2 hour at 300.degree. C. A sample of BTBN-4,
vacuum-dried at 200.degree. C., was submitted for analysis.
Analysis: Calc'd. for C.sub.307 H.sub.162 N.sub.20 O.sub.61 :
C, 72.20; H, 3.20; N, 5.49; O, 19.11.
Found: C, 72.21; H, 3.15; N, 5.44; O, - - - .
EXAMPLE 9
Synthesis of Propargyl-Terminated Oligomeric Polyimide (BTPA-1).
Reaction of BTCA, ODA and Propargyl Amine (2:1:2).
In the m-cresol:benzene azeotropic apparatus was placed a solution
of BTCA (29.001 g., 0.09 mole) in 200 ml. of m-cresol and 50 ml. of
benzene. The mixture was warmed to approximately 50.degree. C. and
a solution of ODA (9.011 g., 0.045 mole) in 150 ml. of m-cresol was
added, forming a slight amount of yellow precipitate. After 10
minutes, a solution of propargyl amine (5 g., 0.0908 mole) in 50
ml. of m-cresol was added and the solution heated to reflux. During
2 hours of reflux, 3.3 ml. of water was collected. After cooling,
the deep red solution was concentrated on a rotary flash
evaporator. A small sample was removed for analysis and
approximately 5 mg. of t-butyl catechol was added to the bulk of
the residue, which was vacuum-dried at 100.degree. C. for 30 hours,
and then at 150.degree. C. for 12 hours, to give sample A, 37.850
g. (95%) as a dark-brown solid. It softened at 270.degree. C.;
partially melted between 280-300.degree. C., but quickly rehardened
at 300.degree. C.
Analysis: Calc'd. for C.sub.52 H.sub.26 N.sub.4 O.sub.11 :
C, 70.75; H, 2.97; N, 6.35; O, 19.94.
Found: C, 70.84; H, 3.13; N, 6.31; O, - - - . EXAMPLE 10
Preparation of Styrene-Terminated Oligomeric Polyimide (BTAS-1).
Reaction of BTCA, ODA and m-Aminostyrene (AS) (2:1:2).
In the m-cresol:benzene azeotropic apparatus was placed a solution
of BTCA (3.222 g., 0.01 mole) in 25 ml. of m-cresol and 10 ml. of
benzene. After warming to approximately 70.degree. C., a solution
of ODA (1.001 g., 0.005 mole) in 15 ml. of m-cresol containing 2
mg. of t-butyl catechol was added, forming an immediate yellow
precipitate. After heating for 15 minutes, a solution of
m-aminostyrene (AS) (1.192 g., 0.01 mole, Sapon Laboratories) in 10
ml. of m-cresol was added and the solution was heated to reflux,
forming a homogeneous solution. After 1 hour of reflux, a
precipitate began to form. After 2 hours of reflux, during which
0.25 ml. of water was collected, the reaction mixture was cooled
and poured into 250 ml. of methanol. After stirring for several
hours, the solid material was filtered off, washed with methanol
and vacuum-dried at 40.degree. C. for 18 hours. The sample still
had a distinct odor of m-cresol. A small portion was removed and
vacuum-dried at 200.degree. C. for 24 hours to give fraction A
whose infrared spectrum was recorded. The remainder of the material
was finely divided and stirred with 50 ml. of ether, and dried at
40.degree. C. to afford 4.0402 g. (80%) of a yellow powder,
fraction B. The infrared spectrum of sample A was substantially the
same as that of sample B.
Sample A softened at 220.degree. C.; was partially molten at
250.degree. C. when pressure was applied; was almost completely
molten at 300.degree. C. when pressure was applied; and rehardened
(cured) to a granular solid after 25 minutes at 300.degree. C.
Sample A was slightly soluble in hot m-cresol.
Sample B softened at 70.degree. C.; was nearly completely molten at
225.degree. C. with applied pressure; and hardened (cured) to a
granular solid at 250.degree. C. Sample B was soluble in hot
m-cresol, and virtually insoluble in sulfolane, DMAC and
toluene.
Analysis: Calc'd. for C.sub.62 H.sub.34 N.sub.4 O.sub.11 :
C, 73.66; H, 3.39; N, 5.54; O. 17.41.
For A Found: C, 73.21; H, 3.67; N, 5.79; O, - - - .
A portion of sample B was postheated in nitrogen at 300.degree. C.
for 24 hours, and a TGA performed in nitrogen at 10.degree.
C./minute, showed an inflection point of 410.degree. C.
EXAMPLE 11
Preparation of N,N'-Di(m-Vinylphenyl)-3,3',4,4'-l
-Benzophenonetetracarboxylic Acid Diimide (BTAS-2). Reaction of
BTCA and AS (1:2).
In the m-cresol:benzene azeotropic apparatus previously described,
fitted with provisions for a nitrogen inlet and outlet, was placed
under nitrogen a warm (70.degree. C.) solution of BTCA (1.2889 g.,
0.004 mole) in 25 ml. of m-cresol and 10 ml. of benzene, containing
1-2 mg. of t-butyl catechol. Then a solution of AS (1.1916 g., 0.01
mole) in 5 ml. of m-cresol was added and the solution heated to
reflux. Reflux with stirring was maintained for 21/2 hours, during
which time approximately 2 ml. of water was collected. After
cooling overnight, the clear solution was reheated and benzene was
distilled off. After cooling, the solution was added dropwise to
150 ml. of methanol; the solid was isolated by filtration and
digested for 15 minutes in 30 ml. of methanol, containing 1-2 mg.
of t-butyl catechol. The washing with methanol was repeated twice
followed with methanol not containing t-butyl catechol. The solid
was filtered off, vacuum-dried at 30.degree. C. for 3 days to give
as a yellow solid
N,N'-di(m-vinylphenyl)-3,3',4,4'-benzophenonetetracarboxylic acid
diimmide (BTAS-2), 1.8567 g. (91%).
BTAS-2 was insoluble in absolute alcohol; it swelled in cold
styrene, was soluble in hot styrene and remained soluble on
cooling; it was soluble in cold tetrahydrofuran, sulfolane,
m-cresol, dioxane and DMAC. The sample appeared to soften at
95-100.degree. C., melted at approximately 180.degree. C., and
rehardened (cured) at 210.degree. C. A sample placed on a block
preheated to 200.degree. C. melted and rehardened within 5
minutes.
Its DTA in nitrogen showed an endotherm at 185.degree. C. (corr.)
followed immediately by an exotherm. Another endotherm occured at
218.degree. C. (corr.) immediately followed by a second
exotherm.
The TGA of BTAS-2 in nitrogen at 10.degree. C./minute showed an
inflection point of approximately 400.degree. C.
Analysis: Calc'd. for C.sub.33 H.sub.20 N.sub.2 O.sub.5 :
C, 75.56; H, 3.84; N, 5.34; O, 10.25.
Found: C, 74.74; H, 3.78; N, 5.71; O, - - - .
EXAMPLE 12
Preparation of Styrene-Terminated Oligomeric Polyimide (BTAS-3).
Reaction of BTCA, DAPB-3,3 and AS (8:7:2).
In the m-cresol:benzene azeotropic apparatus fitted with provisions
for a nitrogen sweep, was placed a warm solution of BTCA (1.2889
g., 0.004 mole) in 25 ml. of m-cresol and 10 ml. of benzene
containing 1-2 mg. of t-butyl catechol. Then a solution of AS
(1.1192 g., 0.01 mole) in 5 ml. of m-cresol was added and the
solution was then stirred and heated at approximately 70.degree. C.
for 15 minutes. Then a solution of DAPB-3,3 (1.023 g., 0.0035 mole)
in 10 ml. of m-cresol was added and the solution heated to reflux
which was maintained for 4 hours, during which time, approximately
1.5 ml. of water was collected. Then the benzene was distilled off.
After cooling to ambient temperature, the slightly hazy solution
was added dropwise to 150 ml. of methanol. The solid was filtered
off and washed three times in 30 ml. of boiling methanol, which
contained a trace of t-butyl catechol, for 15 minutes each time,
then it was given a final wash with inhibitor-free boiling
methanol. The yellow solid was filtered and vacuum-dried at room
temperature for two days to give BTAS-3, 1.782 g. (78%) as a yellow
solid. Its TGA in nitrogen at 10.degree. C./minute showed the
retention of m-cresol solvent.
On a Fisher-Johns melting point block, it melted at
190--195.degree. C., hardened at 205.degree. C., resoftened and
remelted at 210--233.degree. C., and rehardened at 268.degree. C.
Its DTA at 20.degree. C./minute showed a melting endotherm at
183.degree. C. BTAS-3 was soluble in dioxane, m-cresol, DMAC and
sulfolane; it swelled in tetrahydrofuran, styrene, divinylbenzene
and toluene, and was insoluble in methyl ethyl ketone.
A portion of BTAS-3 was vacuum dried at 200.degree. C. for 36 hours
and analyzed.
Analysis: Calc'd. for C.sub.278 H.sub.146 N.sub.16 O.sub.54 : C,
72.99; H, 3.22; N, 4.90; O, 18.89 Found: C, 73.55; H, 3.31; N, 503;
O, - - -.
EXAMPLE 13
Preparation of Styrene-Terminated Oligomeric Polyimide (BTAS-4).
Reaction of BTCA, DAPB-3,3, ODA and AS in 9:(4:4):2 Mole Ratio.
In a large-scale m-cresol:benzene azeotropic apparatus was placed,
under a slow nitrogen sweep, BTCA (21.7505 g. 0.0675 mole), 175 ml.
of m-cresol and 50 ml. of benzene. The mixture was warmed to
approximately 70.degree. C. to dissolve the BTCA and then a
solution of AS (1.7874 g., 0.015 mole) in 25 ml. of m-cresol,
containing 0.1 g. of t-butyl catechol, was added over approximately
1/2 hour. The solution was then refluxed for 20 minutes. Then a
solution of DAPB-3,3 (8.7699 g., 0.030 mole) and ODA (6.0072 g.,
0.030 mole) in 75 ml. of m-cresol was added. Reflux was maintained
for 3 hours; 2.47 ml. of water was collected. Then 50 ml. of
benzene was distilled off.
After cooling to ambient temperature, the clear solution was added
dropwise to 600 ml. of well-stirred methanol. After stirring for 2
hours, the solution was filtered. The isolated solid was heated in
200 ml. of boiling methanol containing approximately 0.1 g. of
t-butyl catechol for 1 hour and filtered. The methanol wash was
repeated three times. A small portion of the solid was removed and
treated in boiling inhibitor-free methanol. This small sample was
used for testing purposes, such as melting behavior, solubility,
etc. The remainder of the material was vacuum-dried at ambient
temperature for 40 hours, to give BTAS-4 as a yellow solid, 36.9 g.
(103%). A TGA in nitrogen showed a loss of approximately 5%
volatiles before an inflection point at approximately 510.degree.
C. The sample was washed once more with hot methanol and
vacuum-dried at 40.degree. C. for 16 hours to give 35.3 g. (98%). A
TGA in nitrogen showed approximately 2% volatiles.
BTAS-4 was soluble in m-cresol and sulfolane, was partially soluble
in hot DMAC and hot N,N-dimethyl formamide DMF, swelled slightly in
dioxane, styrene, 75% DVB and chloroform, but was insoluble in
methanol and benzene. When heated from ambient to higher
temperatures on a Fisher-Johns melting point block, BTAS-4 softened
at 185.degree.-205.degree. C., was partially molten at
approximately 220.degree. C., was a thick melt 235.degree. C., and
hardened after 20 minutes at 300.degree. C. Its TGA in nitrogen
showed an inflection point at approximately 510.degree. C. and a
58% residue at 1000.degree. C. The DTA displayed an endotherm
(softening or melting) in the region of 190.degree. C., which was
followed immediately by a strong exotherm (polymerization) in the
region of 190.degree.-210.degree. C., followed by a weak endotherm
which blends into a second mild exotherm at approximately
260.degree. C. A 0.20 g. sample of BTAS-4 was heated in an air oven
at 200.degree. C. for 5 hours to give BTAS-4-H200. The TGA of
BTAS-4-H200 in nitrogen and in air showed the samples to be
substantially free of m-cresol. The inflection points in nitrogen
and in air are almost identical in the 500.degree. C. region; the
difference in nitrogen and in air is found in a char residue of 60%
to 0% respectively, at temperatures higher than 600.degree. C.
Analysis: Calc'd. for C.sub.289 H.sub.148 N.sub.18 O.sub.57 : C,
72.55; H, 3.12; N, 5.27; 0, 19.06. Found: C, 72.54; H, 3.20; N,
5.32; O, - - -.
EXAMPLE 14
Preparation of Styrene-Terminated Oligomeric Polyimide (BTAS-10R).
Reaction of BTCA, 4,4'-Methylenedianiline (MDA-4,4) and AS
(9:8:2).
In the m-cresol:benzene azeotropic apparatus equipped with a
nitrogen inlet and outlet, there was placed BTCA (21.7505 g.,
0.0675 mole) in 80 ml. of m-cresol and 40 ml. of benzene. The
temperature of the mixture was raised to approximately 70.degree.
C. as nitrogen was passed through the apparatus, and a solution of
m-aminostyrene (AS) (1.7874 g., 0.015 mole) in 40 ml. of m-cresol
containing 0.1 g. of t-butyl catechol was added over 15 minutes,
and the solution was stirred for an additional 15 minutes. Then a
solution of 4,4'-methylenedianiline (MDA-4,4) (11.8956 g., 0.060
mole) in 55 ml. of m-cresol was added and the solution was brought
to reflux. After refluxing for 3 hours, during which 2.35 ml. of
water was collected, a copious yellow precipitate was present.
Then, the benzene was distilled off and the reaction solution was
added dropwise to methanol. The precipitated oligomer was digested
three times in hot methanol containing approximately 0.1 g. of
t-butyl catechol and then vacuum-dried at ambient temperature for
63 hours to afford BTAS-10R, 32.565 g. (98.7%), whose infrared
spectrum was consistent with that expected for the compound.
A 2.25 g. sample of BTAS-10R was washed once with methanol to
remove the inhibitor to afford 2.190 g. of inhibitor-free BTAS-10R,
whose DTA in air showed a slight endotherm at 150.degree. C.,
followed by an exotherm at 175.degree. C.
Analysis: Calc'd. for C.sub.273 H.sub.148 N.sub.10 O.sub.45 : C,
74.52; H, 3..39; N, 5.73; O, 16..36. Found: C, 73.38; H, 3.52; N,
5.84; O, 16.59.
EXAMPLE 15
Preparation of Styrene-Terminated Oligomeric Polyimide BTAS-11).
Reaction of BTCA, 1,3-Di(4-Aminophenoxy)-benzene (DAPB-3,4) and AS
(9:8:2).
By the procedure used in the preparation of Example 14, there was
reacted BTCA (1.8126 g., 0.00563 mole) in 25 ml of m-cresol and 20
ml of benzene, a solution of AS (0.14909) g., 0.00125 mole) in 10
ml. of m-cresol containing 0.1 g. t-butyl catechol, and solution of
1,3-di(4-aminophenoxy)benzene (DAPB-3,4) (1.4617 g., 0.005 mole) in
20 ml. of m-cresol. After refluxing for 5 hours, there was obtained
0.35 ml. of water and solution had not occurred. Then the benzene
was distilled off and the reaction mixture was slowly poured into
methanol to precipitate the oligomer. The oligomer was digested
three times in hot methanol containing 0.1 g. t-butyl catechol and
vacuum-dried at 40.degree. C. to give 3.4882 g. (96.8%) of BTAS-11
as a yellow powder. A small portion of BTAS-11 was digested again
in hot methanol to remove the inhibitor for use in testing. Its
infrared spectrum was consistent with that expected for the
compound.
The TGA in air showed the retention of about 3% m-cresol and an
inflection point in the 500.degree. C. region.
Analysis: Calc'd. for C.sub.313 H.sub.164 N.sub.18 O.sub.61 : C,
72.96; H, 3.21; N, 4.89; O, 18.94. Found: C, 72.22; H, 3.11; N,
4.69; O, - - -.
EXAMPLE 16
Preparation of Styrene-Terminated Oligomeric Polyimide (NTAS-1).
Reaction of 1,4,5,8-Naphthalenetetracarboxylic Acid Dianhydride
(NTCA), DAPB-3,3 and AS (9:8:2).
According to the procedure given above for Example 15, there was
allowed to react 1,4,5,8-naphthalenetetracarboxylic acid
dianhydride (NTCA) (2.8369 g., 0.01125 mole), DAPB-3,3 (2.9233 g.
0.01 mole) and AS (0.2979 g., 0.0025 mole). There was obtained
NTAS-1, as a tan powder which partially melted, with darkening at
220.degree.-260.degree. C., rehardened at 265.degree. C, and then
did not change up to 300.degree. C. When a sample was placed on
Fisher-Johns apparatus at approximately 220.degree. C., it became
completely molten by 260.degree. C. and rehardened at about
265.degree. C.
NTAS-1 was soluble in DMAC, m-cresol, sulfolane and concentrated
sulfuric acid, and swelled in hot dioxane. Its infrared spectrum
was consistent with that expected for the compound.
Analysis: Calc'd. for C.sub.286 H.sub.146 N.sub.18 O.sub.52 : C,
73.61; H, 3.15; N, 5.40; O, 17.83. Found: C, 73.74; H, 3.50; N,
5.83; O, - - -.
EXAMPLE 17
Preparation of Styrene-Terminated Oligomeric Polyimide (PMAS-1).
Reaction of Pyromellitic Anhydride (PMA), DAPB-3,3 and AS
(9:8:2).
According to the procedure given above for Example 15, there was
allowed to react pyromellitic anhydride (PMA) (2.4538 g., 0.01125
mole), DAPB-3,3 (2.9233 g., 0.01 mole) and AS (0.2979 g., 0.0025
mole). Complete solution did not occur during the reaction period.
There was obtained PMAS-1, which melted at 150.degree.-210.degree.
C., rehardened at 240.degree. C., and resoftened at 275.degree. C.,
and rehardened after 20 minutes at 300.degree. C. PMAS-1 swelled in
m-cresol, and was insoluble in concentrated sulfuric acid, hot
DMAC, sulfolane and dioxane. Its infrared spectrum was consistent
with that expected for the compound. Its DTA in air and its TGA in
air showed solvent retention and an inflection point in the
500.degree. C. region.
Analysis: Calc'd. for C.sub.250 H.sub.128 N.sub.18 O.sub.52 : C,
71.22; H, 3.06; N, 5.98; O, 1974. Found: C, 71.22; H, 3.22; N,
6.17; O, - - -.
EXAMPLE 18
Preparation of Polyimide (PI-1). Reaction of BTCA and ODA
(1:1).
In a m-cresol:benzene azeotropic apparatus equipped with a nitrogen
inlet and outlet tube a solution of BTCA (12.899 g., 0.04 mole) in
50 ml. of dry DMAC was prepared at 40.degree. C. To this solution,
a solution of ODA (8.0096 g., 0.04 mole) in 50 ml. of DMAC was
added during the course of 30 minutes, yielding an amber-colored
viscous solution which was heated further at 40.degree. C. for 30
minutes and at 85.degree. C. for 1 hour. After cooling the solution
to 50.degree. C., acetic anhydride (12.25 g., 0.12 mole) was added
slowly. A yellow precipitate, which formed as the acetic anhydride
was added, redissolved with continued stirring. The clear viscous
solution was heated at 85.degree. C. for 1 hour, during which time
a thick yellow precipitate formed. The reaction mixture was cooled
and poured into 400 ml. of methanol and stirred. The yellow solid
was collected by filtration washed with methanol and dried in a
vacuum oven at 100.degree. C. 19.5 g. (.about.100%);
m.p.>400.degree. C. The polymer was soluble in hot
N-methyl-2-pyrrolidone and in hot m-cresol, but insoluble in DMAC.
A sample block-dried at 150.degree. C. was analyzed.
Its infrared spectrum showed a strong peak at 5.82.mu. and a
shoulder at 5.63.mu. for the cyclic imide structure; and a broad
band in the 3.mu. region for carboxyl. A 4 g. sample of the polymer
was reheated with 15 ml. of acetic anhydride at 140.degree. C. for
6 hours, cooled and the yellow solid (3.96 g.) was collected by
filtration, washed with methanol and dried in a vacuum oven at
140.degree. C. Its infrared spectrum was identical with that of the
untreated sample; a sample block-dried at 150.degree. C. was
analyzed.
Analysis: Calc'd. for C.sub.29 H.sub.14 N.sub.2 O.sub.6 : C, 71.61;
H, 2.90; N, 5.76. Found: C, 70.50; H, 2.77; N, 5.88.
EXAMPLE 18a
In a m-cresol:benzene azeotropic apparatus was placed
4,4'-methylene dianiline (MDA) (1.98 g., 0.01 mole), pyromellitic
anhydride (PMA) (2.18 g., 0.01 mole) 35 ml. of m-cresol and 10 ml.
of benzene. The mixture was heated to 100.degree.-105.degree. C.
and at the end of 30 minutes 0.18 g. of water was collected in the
trap. Then the trap was removed and the benzene recovered by
distillation leaving a clear solution of completely cycled
polyimide.
EXAMPLE 18b
The composition of Example 18a consisting of the same amounts of
MDA, PMA, benzene and m-cresol were placed in a distillation flask
equipped with a condenser, receiver, etc. On heating to
100.degree.-105.degree. C. some water-benzene azeotrope distilled
at 69.4.degree. C. but the vapor temperature rose slowly and
increased to that of benzene with none of the benzene being
recycled to the reaction mixture. Within 20 minutes, all of the
benzene had distilled from the reaction mixture, the pot
temperature rose to 145.degree.-150.degree. C., and the contents of
the flask gelled and precipitated from the m-cresol. Titration of a
sample of the precipitated polymer with standardized base gave
values which corresponded to 81% cyclization; in addition the
polymer was crosslinked and insoluble in m-cresol, DMF and
DMAC.
EXAMPLE 19
Preparation of Polyimide (PI-7). Reaction of BTCA and DAPB-3,3
(1:1) and Some Postreactions of PI-7.
In a m-cresol:benzene azeotropic apparatus was placed
1,3-di(3-aminophenoxy)benzene (1.4617 g., 0.005 mole), BTCA (1.611
g., 0.005 mole), 40 ml. of m-cresol and 10 ml. of benzene. An
initial precipitate dissolved after 20 minutes at
60.degree.-70.degree. C., to give an orange solution. As soon as
reflux began, water collected in the DEAN-Stark trap, and at the
end of 41/2 hours, 0.18 ml. of water was collected. The Dean-Stark
trap was removed and a distillation head, with a collection
apparatus substituted in its place; approximately 7.5 ml. of
benzene was collected.
A 10 ml. portion of the polymer solution was added dropwise to 50
ml. of stirred methanol. The solid was collected by filtration and
stirred for 15 minutes in fresh hot methanol; the methanol washing
was repeated twice, the solid recovered and vacuum-dried at
70.degree. C. for 24 hours, to give PI-7 (0.6144 g.). When PI-7 was
heated on a Fisher-Johns melting point block, it softened in the
region of 100.degree. C., was quite soft at 187.degree. C., was
partially molten at 225.degree. C. with applied pressure, was
completely molten at 245.degree. c., and did not harden when heated
slowly up to 300.degree. C.
PI-7 was insoluble in carbon tetrachloride, tetrachloroethylene,
methyl ethyl ketone, ether, ethyl acetate, 2-propanol, absolute
ethanol, and benzene; it swelled in hot chlorobenzene, hot toluene,
vcold chloroform, and cold tetrahydrofuran, and was soluble in
m-cresol, DMAC, sulfolane and dioxane (b.p. 100.degree. C.).
A film (A) was cast from a 5.00 ml. portion of the polymer solution
which contained 0.063 g./ml. of PI-7. The film was cured at
100.degree. C. for 18 hours, then the temperature was raised to
200.degree. C. over 6 hours, and maintained at 200.degree. C. for
21/2 days, followed by 300.degree. C. for 24 hours to give film A,
which was insoluble in hot m-cresol.
Another film (B) was prepared by the procedure given for film A by
using 4.0 ml. (0.0005 mole of polymer) of the polymer solution to
which was added a solution of oxydianiline (0.020 g., 0.0001 mole)
in 1.0 ml. m-cresol. The film was insoluble in hot m-cresol.
The adhesion of films A and B to the glass casting plate was
sufficiently high that the films could not be lifted after
immersion in water, water-5% DMAC or dioxane for 7 days at
temperatures of 80.degree.-100.degree. C. The films were released
by soaking, at 70.degree. C. for 48 hours, in DMAC, in which the
300.degree. C. cured films were insoluble.
A solution sample of approximately 21 ml. of Polyimide PI-7 was
heated at 115.degree. C. for 18 hours, then at 200.degree. C. for
24 hours. An observable increase in viscosity was noted. About 14
ml. of m-cresol was removed by distillation and the polymer
precipitated in methanol and vacuum-dried at 50.degree. C. for 20
hours, to yield 1.283 g. (97%) of PI-7, inherent viscosity in
m-cresol (0.5%), 0.27 dl/g and in concentrated sulfuric acid
(0.5%), 0.30 dl./g. PI-7a was soluble in the same solvents as PI7,
namely, m-cresol, DMAC, sulfolane and dioxane. The thermal behavior
of PI-7a, for example, such as softening, hardening, etc. was the
same as PI-7. The TGA inflection point of PI-7a of approximately
525.degree. C. in nitrogen and the 60% residue at 1000.degree. C.
was the same as PI-7. The TGA inflection point in air was the same
as PI-7 at approximately 500.degree. C., showing a zero char
residue at 800.degree. C. due to burning.
Analysis: Calc'd. for C.sub.35 H.sub.18 N.sub.2 O.sub.7 : C, 72.66;
H, 3.14; N, 4.84; O, 19.36. Found: C, 72.44; H, 3.18; N, 4.87; O, -
- -.
EXAMPLE20
Polyimide (PI-8). Copolymer Reaction of BTCA with DAPB-3,3 and ODA
(2:0.5:1.5).
This polymer was prepared from DAPB-3,3 (0.365 g., 0.00125 mole),
ODA (0.705 g., 0.00375 mole), and BTCA (1.611 g., 0.005 mole) in
which the mole ratio is 0.5:1.5:2.0, by the azeotropic technique,
precipitated in methanol and vacuum-dried at 70.degree. C. The
polymer was soluble in m-cresol, DMAC and sulfolane but insoluble
in dioxane. It softened and flowed with applied pressure in the
range of 230.degree.-280.degree. C.; rehardened by 300.degree. C.;
.eta.inh (0.5% m-cresol) 0.525 dl./g. The thermal stabilities in
nitrogen and in air of PI-8 dried at 70.degree. C. and at
200.degree. C. were substantially identical to PI-7 treated
similarly.
Analysis: Calc'd for C.sub.122 H.sub.70 N.sub.8 O.sub.25 :
C, 71.55; H, 3.45; N, 5.47; O, 19.53. Found: C, 70.70; H, 3.01; N,
5.46; O, - - - .
The example can be repeated using xylene and toluene as the
azeotroping agent resulting in an azeotroping temperature about 10
to 15.degree. C. higher than for benzene.
EXAMPLE 21
Preparation of (PI-15). Reaction of BTCA and SDA-3,3 (1:1.1) and
Bodying in Air.
In a m-cresol:benzene azeotropic apparatus equipped with a
mechanical stirrer, Dean-Stark trap and condenser was placed BTCA
(17.6150 g., 0.050 mole) and SDA-3,3 (13.6670 g. 0.055 mole) with
75 ml. of m-cresol and 25 ml. of benzene. The mixture was stirred
and heated to reflux. During 3 hours of reflux 1.75 ml. of water
was collected. Then the Dean-Stark trap was removed and a
distillation apparatus was substituted in its place and solvent was
distilled off until m-cresol (b.p. 202.degree. C.) began to distill
over. The distillation apparatus was removed and a reflux condenser
installed in its place, and reflux was maintained for 121/2 hours.
Then a small portion was removed and the polymer (PI-15A) was
precipitated with methanol, which, after vacuum-drying at
70.degree. C., had an .eta..sub.inh (as a 0.5% solution in
m-cresol) of 0.409 dl./g.
After an additional 30 hours of reflux, a sample of the polymer was
precipitated with methanol to give PI-15B as a light-yellow solid
whose .eta..sub.inh as a 0.5% solution in m-cresol was 0.43 dl./g.
After an additional 54.5 hours of reflux the bulk of the reaction
solution was added to methanol and the resulting light-brown
polymer (PI-15C) had an .eta..sub.inh as a 0.5% solution in
m-cresol of 0.295 dl./g. which indicated that bodying of such
polyimides is preferably performed in the absence of air and in an
inert atmosphere such as N.sub.2, He, CO, CO.sub.2, argon, etc.
Upon pouring off the reaction solution a gelled film on the inside
of the reaction flask was found. After grinding the gel in a
mechanical blender with methanol and vacuum-drying, there are
obtained 1.75 g. of a dark solid, PI-15d.
The weight of PI-15A was 0.80 g.; PI-15B, 4.37 g.; PI-15C, 21.35
g.; and PI-15D, 1.75 g. (5.8%): total yield, 28.27 g. (96%).
EXAMPLE 22
Preparation of Phenyl-Terminated Oligomeric Polyimide (BTOB-1).
Reaction of BTCA, ODA and Aniline (2:1:2).
In a m-cresol:benzene azeotropic apparatus described previously,
there was placed a solution of BTCA (3.222 g., 0.01 mole) in 25 ml.
of m-cresol and 15 ml. of benzene. After warming to approximately
50.degree. C., a solution of ODA (1.001 g., 0.005 mole) in 15 ml.
of m-cresol was added, forming a copious yellow precipitate. After
10 minutes, a solution of freshly-distilled aniline (1.02 g., 0.011
mole) in 10 ml. of m-cresol was added. The reaction mixture was
heated to reflux forming an orange solution. During 2 hours of
reflux, 0.30 ml. of water was collected and a precipitate had
formed. After cooling, the solvents were removed on a rotary flash
evaporator and the residue dried in a vacuum oven at 100.degree.
C., to yield a yellow solid, 4.6390 g. (97%). Its infrared spectrum
was consistent with the structure expected for the compound. On a
Fisher-Johns melting point apparatus, it softened at 110.degree.
C., partially melted by 230.degree. C., and rehardened at
235.degree. C. It was soluble in hot m-cresol and insoluble in hot
DMAC.
An intimate mixture of BTOB-1 and ODA in a molar ratio of 1:2 was
placed on a Fisher-Johns apparatus previously heated to 250.degree.
C. The mixture melted, and as the color changed from yellow to
reddish-orange, it hardened and did not remelt when heated to
300.degree. C.
Analysis: Calc'd. for C.sub.58 H.sub.30 N.sub.4 O.sub.11 : C,
72.65; H, 3.15; N, 5.84; O, 18.36. Found: C, 73.00; H, 3.43; N,
4.66; O, - - -.
EXAMPLE 23
Preparation of Phenolic-Terminated Oligomeric Polyimide (BTAP-1).
Reaction of BTCA, ODA and p-Aminophenol (2:1:2).
In the m-cresol:benzene azeotropic apparatus was placed a solution
of BTCA (3.222 g., 0.01 mole) in 25 ml. of m-cresol and 15 ml. of
benzene. After warming to 50.degree. C., a solution of ODA (1.001
g., 0.005 mole) in 15 ml. of m-cresol was added, forming an
immediate yellow precipitate. Further heating did not dissolve the
precipitate, and, after 10 minutes, a slurry of freshly purified
p-aminophenol (m.p. 190.degree.-193.degree. C.; g., 0.01 mole) in
10 ml. of m-cresol was added. At reflux, the solid dissolved
forming an orange solution. During 2 hours of reflux, 0.20 ml. of
water was collected and a precipitate formed. Then, the solvents
were removed on a rotary flash evaporator and the residue was
vacuum-dried at 170.degree. C., yielding a yellow solid, 4.907 g.
(99%). Its infrared spectrum was consistent with the structure
expected for the compound. It softened slightly at 50.degree. C.,
was almost completely melted at 265.degree.-280.degree. C.; and
rehardened at 283.degree. C. It was soluble in hot m-cresol, hot
DMAC and hot sulfolane..
Analysis: Calc'd. for C.sub.58 H.sub.30 N.sub.4 O.sub.13 : C,
70..30; H, 3,05; N, 5.65; O, 20.99. Found: C, 70.04; H, 3.01; N,
5.73; O, - - -.
EXAMPLE 24
Preparation of Amine-Terminated Oligomeric Polyimide (BTAT-2).
Reaction of BTCA and ODA (3:4).
In a m-cresol:benzene azeotropic apparatus was placed a solution of
ODA (3.004 g., 0.016 mole) in 20 ml. of m-cresol and 10 ml. of
benzene. After warming to 60.degree. C., a solution of BTCA (3.867
g., 0.012 mole) in 30 ml. of m-cresol was added. A copious yellow
precipitate formed immediately. The reaction mixture was heated to
reflux and the solid material dissolved, forming an orange
solution. During 2 hours of reflux 0.35 ml. of water was collected
and a precipitate formed in the reaction flask. After cooling, the
reaction mixture was concentrated to approximately one-third the
original volume on a rotary flash evaporator. The mixture was then
added to 150 ml. of methanol and allowed to stand for 10 hours. The
solids were filtered off, digested twice in hot methanol, isolated
and dried in a vacuum oven at 170.degree. C., to yield a yellow
solid, 6.311 g. (96%). It softened very slightly at 70.degree. C.,
at 235.degree. C. it rehardened and did not melt when heated up to
300.degree. C. It was very slightly soluble in hot m-cresol, hot
DMAC and hot sulfolane. Its infrared spectrum was consistent with
that expected for the structure of the oligomer.
Analysis: Calc'd. for C.sub.99 H.sub.54 N.sub.8 O.sub.19 : C,
71.65; H, 3.28; N, 6.75; O, 18.32. Found: C, 71.21; H, 3.03; N,
6.63; O, - - -.
EXAMPLE 25
Preparation of Amine-Terminated Oligomeric Polyimide (BTAT-3).
Reaction of BTCA and ODA (7:8).
In the m-cresol:benzene azeotropic apparatus was placed
4,4'-oxydianiline (ODA) (3.204 g., 0.016 mole) in 20 ml. of
m-cresol and 10 ml. of benzene. After warming to 60.degree. C., a
solution of BTCA (4.512 g., 0.014 mole) in 30 ml. m-cresol was
added. A copious yellow precipitate formed immediately. The
reaction mixture was heated to reflux and the solid material
dissolved, forming an orange solution. After 2 hours of reflux,
0.30 ml. of water had been collected and a precipitate had formed
in the reaction flask. After cooling, the reaction mixture was
concentrated on a rotary flash evaporator and then vacuum-dried at
170.degree. C. to give 7.0960 g. (.about.100%) of a yellow solid
which was slightly soluble in m-cresol, and insoluble in sulfolane
and DMAC. On a Fisher-Johns melting point apparatus it softened
slightly at about 210.degree. C., partially melted by 235.degree.
C., and rehardened to a granular solid at 240.degree. C.
Analysis: Calc'd. for C.sub.215 H.sub.110 N.sub.16 O.sub.43 : C,
72.18; H, 3.10; N, 5.48. Found: C, 70.26; H, 3.26; N, 6.11.
When the above procedure was repeated but the azeotropic agent was
omitted, and the condensation performed by heating, benzene and
some water distilled off, then benzene distilled off and when
heating was continued the temperature in the flask rose and
approached the b.p. of m-cresol. Before condensation and
cyclization was complete, gellation occurred. The acid value of the
isolated product indicated that about 20% of the carboxylic groups
were not cyclized.
EXAMPLE 26
Preparation of Oligomeric Anhydride (BTOD-2). Reaction of BTCA and
ODA (2:1).
In a 250-ml. three-neck, round-bottom flask equipped with a
mechanical stirrer, dropping funnel, condenser, etc. a solution of
BTCA (6.444 g., 0.02 mole) in 75 ml. of acetonitrile was prepared,
at the reflux temperature (82.degree. C.) of the acetonitrile.
Then, a solution of ODA (2 g., 0.01 mole) in 50 ml. of warm
(35.degree. C.) acetonitrile was added slowly dropwise, forming a
light-yellow precipitate. After the addition, the mixture was
refluxed for 1/2 hour, and acetonitrile was removed in a rotary
flash evaporator. The solid was dried in a vacuum oven at
80.degree. C.; yield (A) 8.45 g. (100%) which was soluble in hot
DMAC and N-methyl-2-pyrrolidone; but attempts to crystallize the
product from these solvents were unsuccessful. The crude sample
melts in a Fisher-Johns melting point apparatus in the range of
200.degree.-210.degree. C. Its infrared spectrum shows the peaks
for anhydride groups at 5.38 and 5.6.mu., but also shows a broad
band at 2.8 to 3.6.mu., which is attributable to carboxylic --OH,
indicating the presence of some hemiamic acid structures and, thus,
not complete cyclization.
In a 25-ml. round-bottom flask, equipped with a reflux condenser
and drying tube, 1.4 g. of (A) was heated with 10 ml. of acetic
anhydride at a reflux temperature of 140.degree. C., to give a
solution containing a small amount of a viscous, gummy product.
Heating at reflux was continued for 21/2 hours, and then allowed to
cool. A bright-yellow precipitate was collected by filtration,
washed with benzene and dried, to obtain fraction B (350 mg.), m.p.
>300.degree. C. The infrared spectrum of B showed that
cyclization was now complete.
The filtrate, on evaporation to dryness, yielded (C) (1 g.), which
softened at 90.degree.-100.degree. C. (Fisher-Johns Melting Point
Apparatus); it melted to a clear liquid at 198.degree.-205.degree.
C. in a melting point tube. Its infrared spectrum showed strong
peaks for anhydride at 5.4 and 5.62.mu..
EXAMPLE 27
Preparation of Maleimide-Terminated Oligomeric Polyimide (BTMI-3).
Reaction of BTCA, SDA-3,3 and Maleic Anhydride (8:9:2).
In the m-cresol:benzene azeotropic apparatus, there was placed
SDA-3,3 (2.2320 g. (0.009 mole) in 15 ml. of m-cresol and 10 ml. of
benzene. After warming to approximately 50.degree. C., a solution
of maleic anhydride (0.1961 g., 0.002 mole) in 15 ml. of m-cresol
was added over about 1/2 hour. The resulting solution was heated at
100.degree. C. for 1 hour, and then a solution of BTCA (2.5778 g.,
0.008 mole) in 20 ml. of m-cresol was added. The solution was
heated to reflux, and over 11/2 hours 0.27 ml. of water was
collected. After cooling the reaction mixture was concentrated on a
rotary flash evaporator and the residue was vacuum-dried at
150.degree. C. for 30 hours. The residue was then dissolved in 30
ml. of m-cresol at 70.degree.-80.degree. C. and acetic anhydride
(0.4686 g., 0.00261 mole) and sodium acetate (0.0215 g., 0.000261
mole) were added. The solution was heated and stirred at 70
-80.degree. C. for 4 hours. The oligomer was then precipitated with
methanol and was washed three times with hot methanol to yield,
after vacuum-drying at 110.degree. C., 4.6 g. (94%) of a yellow
solid whose infrared spectrum was consistent with the structure of
the expected compound. BTMI-3 began to melt at 260.degree. C. but
did not completely melt by 300.degree. C. It was soluble in hot
m-cresol, swelled considerably in hot DMAC and hot sulfolane.
The TGA in air of BTMI-3 showed a weight loss of approximately 7%
below 300.degree. C., due to retained m-cresol. A small sample was
dried at 300.degree. C. for 1 hour to give BTMI-3-H300, whose TGA
in air shows a break at 400.degree. C. and an inflection point in
excess of 500.degree. C.
Analysis: Calc'd. for C.sub.252 H.sub.124 N.sub.18 O.sub.62 S.sub.9
: C, 64.61; H, 2.67; N, 5.38; O, 21.18; S, 6.16. Found: C, 64.34;
H, 2.95; N, 5.43; O, - - - ; S, - - - .
EXAMPLE 28
a. Preparation of Maleimide-Terminated Oligomeric Polyimide
(BTMI-4). Reaction of BTCA, SDA-4,4 and Maleic Anhydride
(8:9:2).
In the m-cresol:benzene azeotropic apparatus there was place
SDA-4,4 (2.2320 g., 0.009 mole) in 15 ml. of m-cresol and 10 ml. of
benzene. After warming to approximately 50.degree. C., a solution
of maleic anhydride (0.1961 g., 0.002 mole) in 15 ml. of m-cresol
was added over about 1/2 hour. The resulting solution was heated at
100.degree. C. for 1 hour, and then a solution of BTCA (2.5778 g.,
0.008 mole) in 20 ml. of m-cresol was added. The solution was
heated to reflux and over 11/2 hours 0.27 ml. of water was
collected. After cooling, the reaction mixture was concentrated on
a rotary flash evaporator and the residue was vacuum-dried at
150.degree. C. for 30 hours. The residue was then dissolved in 30
ml. of m-cresol at 70.degree.-80.degree. C. and acetic anhydride
(0.4685 g., 0.00261 mole) and sodium acetate (0.0215 g., 0.000261
mole) were added. The solution was heated and stirred at
70.degree.-80.degree. C. for 4 hours. The oligomer was then
precipitated with methanol and was washed 3 times with hot methanol
to yield, after vacuum-drying at 110.degree. C., 4.3 g. (88%) of a
yellow solid whose infrared spectrum was consistent with that
expected for the compound, and very similar to that of BTMI-3.
BTMI-4 began to melt at 255.degree. C. but did not completely melt
by 300.degree. C. It was soluble in hot m-cresol, DMAC and
sulfolane.
The TGA in air of BTMI-4 showed a loss of approximately 7% below
300.degree. C., due to retained solvent. A small sample was dried
at 300.degree. C. for 1 hour to give BTMI-4-H300 whose TGA in air
is identical with that of BTMI-3-H300 and showed an inflection
point in excess of 500.degree. C.
Analysis: Calc'd. for C.sub.252 H.sub.124 N.sub.18 O.sub.62 S.sub.9
: C, 64.61; H, 2.67; N, 5.38; O, 21.18; S, 6.16. Found: C, 64.35;
H, 2.81; N, 5.53; O, - - - ; S, - - - .
b. Preparation of Maleamic Acid-Terminated Oligomeric Polyimide
(BTMA-1). Reaction of BTCA, ODA and Maleic Anhydride (1:2:2).
In the m-cresol:benzene azeotropic apparatus was placed
oxydianiline (ODA) (4.004 g., 0.02 mole) in 15 ml. of m-cresol and
10 ml. of benzene. After warming to 40.degree. C., a solution of
maleic anhydride (1.961 g., 0.02 mole) in 15 ml. of m-cresol was
added to give a red solution, which was heated at
90.degree.-100.degree. C. for 1 hour. A yellow precipitate soon
formed which did not redissolve. Then BTCA (3.222 g., 0.01 mole) in
35 ml. of m-cresol was added. The temperature was maintained at
90.degree.-100.degree. C. for 1 hour. Solution did not occur. Then
the temperature was raised to approximately 110.degree. C. (reflux)
and maintained for 11/2 hours. No water was collected in the
Dean-Stark trap. Then the reaction mixture was cooled, the solvent
removed on a rotary flash evaporator and the residue was
vacuum-dried at 150.degree. C. for 24 hours to yield the hemiamic
acid, 8.7088 g. (95%). The product was partialy soluble in hot
m-cresol and was insoluble in DMAC, sulfolane and acetic
anhydride.
Analysis: Calc'd. for (hemiamic acid) C.sub.49 H.sub.30 N.sub.4
O.sub.13 : C, 66.66; H, 3.43; N, 6.30; O, 23.56. Found: C, 66.60;
H, 3.55; N, 6.46; O, - - - .
EXAMPLE 29
Preparation of Phenol-Terminated Oligomeric Polyimide (BTAP-3).
Reaction of BTCA, DAPB-3,3 and p-Aminophenol (9:8:2).
In the m-cresol:benzene azeotropic apparatus there was allowed to
react BTCA (4.3501 g., 0.0135 mole), DAPB-3,3 (3.5080 g., 0.012
mole) and p-aminophenol (0.3274 g., 0.003 mole). There was obtained
7.5784 g. (98.5%) of a light-yellow solid (BTAP-3) after
vacuum-drying at 70.degree. C. On a Fisher-Johns melting point
apparatus BTAP-3 melted from 205.degree. C., to 220.degree. C.,
thickened above 235.degree. C. but did not reharden during 15
minutes at 300.degree. C. BTAP-3 was soluble in m-cresol, DMAC,
sulfolane and dioxane, swelled in hot chloroform, hot methylene
chloride and hot tetrahydrofuran. It formed a separate oily phase
in hot epichlorohydrin. The TGA in air data are given in Table
I.
Analysis: Calc'd. for C.sub.309 H.sub.160 N.sub.18 O.sub.63 : C,
72.31; H, 3.14; N, 4.91; O, 19.64. Found: C, 72.00; H, 3.29; N,
4.95; O, - - - .
EXAMPLE 30
Preparation of Phenol-Terminated Oligomeric Polyimide (BTAP-5R).
Reaction of BTCA, DAPB-3,3 and p-Aminophenol (5:4:2).
According to the m-cresol:benzene technique there was allowed to
react BTCA (3.2223 g., 0.01 mole), DAPB-3,3 (2.3386 g., 0.008 mole)
and p-aminophenol (0.4365 g., 0.004 mole). There was obtained
5.2805 g. (93.8%) of a fine yellow powder (BTAP-5R) which was
soluble in m-cresol, DMAC, sulfolane and dioxane. On a Fisher-Johns
melting point apparatus BTAP-5R melted at 180.degree.-215.degree.
C. and did not reharden on being heated at 300.degree. C. for 40
minutes. The lowest temperature at which a sample would melt
completely when dropped onto the preheated stage was 205.degree. C.
The TGA in air data are given in Table I.
Analysis: Calc'd. for C.sub.169 H.sub.88 N.sub.10 O.sub.35 :
(BTAP-5R) C, 72.01; H, 3.15; N, 4.97; O, 19.87. Found: C, 71.93; H,
3.22; N, 4.93; O, - - - .
Example 31
Preparation of Phenol-Terminated Oligomeric Polyimide (BTAP-6).
Reaction of BTCA, DAPB-3,3 and p-Aminophenol (5:4:2) with Inverse
Order of Addition of the Amine.
According to a modification of the m-cresol: benzene azeotropic
technique there was allowed to react BTCA (3.2223 g., 0.01 mole)
and DAPB-3,3 (2.3386 g., 0.008 mole) for 5 hours. Then
p-aminophenol (0.4365 g., 0.004 mole) was added and the reaction
continued for an additional 5 hours. The reaction solution was
slightly hazy. After the usual isolation procedure there was
obtained BTAP-6 as a light yellow solid, 5.4177 g. (96%). On a
Fisher-Johns melting point apparatus BTAP-6 melted over the range
192.degree.-205.degree. C. and did not reharden when heated at
300.degree. C. for 30 minutes. The lowest temperature at which a
sample would melt when dropped onto the preheated stage was
205.degree. C.
BTAP-6 was soluble in m-cresol, DMAC, DMF, sulfolane and dioxane.
However, when a small sample was added to preheated dioxane or
preheated DMAC, most of the sample formed a gelled mass which did
not dissolve on further heating. The infrared spectrum of BTAP-6
was identical to the infrared spectrum of BTAP-5R. The DTA in
nitrogen of BTAP-6 displayed a broad endotherm centered at
175.degree. C., followed by a mild exotherm and then another
endotherm at 270.degree. C. The DTA in nitrogen of BTAP-5R showed
similar peaks. The TGA data in air are given in Table I.
EXAMPLE 32
Preparation of Amine-Terminated Oligomeric Polyimide (BTAT-4).
Reaction of BTCA and SDA-3,3 (4:5).
In a m-cresol:benzene azeotropic apparatus was placed BTCA (11.2781
g., 0.035 mole), SDA-3,3 (10.8760 g., 0.0438 mole), 80 ml. of
m-cresol and 10 ml. of benzene. The mixture was refluxed for 31/2
hours during which time 1.3 ml. of water was collected. Then, the
benzene was distilled off and the solution was precipitated in
methanol. The precipitated oligomer was digested three times in hot
methanol and then vacuum dried at 70.degree. C. for 24 hours to
give BTAT-4, 19.7498 g. (95%) as a light-yellow solid which was
soluble in m-cresol, DMAC and sulfolane. It swelled in hot dioxane.
On a Fisher-Johns apparatus, it softened slightly above 180.degree.
C., melted at 245.degree.-280.degree. C. and rehardened after 5
minutes at 300.degree. C. The lowest temperature at which a sample
would melt completely dropped onto the preheated block was
270.degree. C. The TGA in air data are given in Table I.
A sample was vacuum-dried at 200.degree. C. and submitted for
analysis.
Analysis: Calc'd. for C.sub.128 H.sub.68 N.sub.10 O.sub.30 S.sub.5
: C, 64.42; H, 2.87; N, 5.87; O, 20.12; S, 6.72. Found: C, 63.71;
H, 2.91; N, 5.75; O, - - - ; S, - - - .
EXAMPLE 33
Preparation of Amine-Terminated Oligomeric Polyimide (BTAT-5).
Reaction of BTCA and SDA-3,3 (8:9).
According to the procedure used in Example 32, there was allowed to
react BTCA (11.2781 g., 0.035 mole) and SDA-3,3 (9.7834 g., 0.0394
mole) in 80 ml. of m-cresol and 10 ml. of benzene. There was
obtained the oligomer, BTAT-5, as a light-yellow solid, 18.3 g.
(92.5%) which was soluble in m-cresol, DMAC and sulfolane. It
swelled in hot dioxane. On a Fisher-Johns apparatus it began to
melt at 225.degree. C. but was not completely melted by 300.degree.
C., at which temperature it hardened in 3 minutes. The lowest
temperature at which a sample would melt completely when dropped
onto the preheated block was 280.degree. C. The TGA in air data are
given in Table I.
The analysis was performed on a small sample vacuum-dried at
200.degree. C.
Analysis: Calc'd. for C.sub.244 H.sub.124 N.sub.18 O.sub.58 S.sub.9
: C, 64.77; H, 2.76; N, 5.57; O, 20.51; S, 6.38. Found: C, 63.54;
H, 2.81; N, 5.45; O, - - - ; S, - - - .
EXAMPLE 34
Preparation of Amine-Terminated Oligomeric Polyimide (BTAT-6).
Reaction of BTCA and DAPB-3,3 (4:5).
According to the procedure for example 32, BTCA (3.2223 g., 0.01
mole) and DAPB-3,3 (3.7529 g., 0.0125 mole) were allowed to react.
There was obtained BTAT-6, 6.1215 g. (94%) as a yellow powder. On a
Fisher-Johns melting point apparatus BTAT-6 melted from
180.degree.-200.degree. C. and rehardened after 30 minutes at
300.degree. C. The lowest temperature at which a sample completely
melted when dropped onto a preheated block was 190.degree. C.
BTAT-6 was soluble in m-cresol, DMAC, sulfolane and dioxane. The
TGA in air data are given in Table I.
A sample was vacuum-dried at 200.degree. C. for analysis.
Analysis: Calc'd. for C.sub.158 H.sub.88 N.sub.10 O.sub.30 : C,
72.81; H, 3.40; N, 5.37; O, 18.42. Found: C, 72.72; H, 3.35; N,
4.77; O, - - - .
EXAMPLE 35
Preparation of Amine-Terminated Oligomeric Polyimide (BTAT-7).
Reaction of BTCA and DAPB-3,3 (8:9).
According to the procedure for Example 32, BTCA (3.2223 g., 0.01
mole) and DAPB-3,3 (3.2887 g., 0.01125 mole) were allowed to react.
There was obtained BTAT-7 as a yellow powder, 5.8708 g. (95.4%). On
a Fisher-Johns apparatus BTAT-7 began to melt from 190.degree. C.
but did not completely melt by 300.degree. C., when it hardened in
30 minutes. The lowest temperature at which a sample melted when
dropped onto a preheated block was 220.degree. C. BTAT-6 was
soluble in m-cresol, DMAC, sulfolane and dioxane. The TGA in air
data are given in Table I.
A small sample was vacuum-dried at 200.degree. C. for analysis.
Analysis: Calc'd. for C.sub.298 H.sub.160 N.sub.18 O.sub.58 : C,
72.74; H, 3.28; N, 5.12; O, 18.86. Found: C, 72.45; H, 3.31; N,
5.04; O, - - - .
EXAMPLE 36
Preparation of Anhydride-Terminated Oligomeric Polyimide (BTOD-3).
Reaction of BTCA and SDA-3,3 (5:4).
According to the procedure used for Example 32, there was allowed
to react BTCA (12.0827 g., 0.0375 mole) and SDA-3,3 (7.4493 g.,
0.03 mole) in 80 ml. of m-cresol and 10 ml. of benzene. There was
obtained the oligomer BTOD-3, as a light-yellow solid, 16.9 g.
(92%) which was soluble in m-cresol, DMAC, DMF and sulfolane. It
softened at 240.degree. C., melted from 245.degree.-265.degree. C.,
with the evolution of small amounts of gas, and did not harden
during 30 minutes at 300.degree. C. The lowest temperature at which
a sample melted completely when dropped onto a preheated block was
255.degree. C.
A small sample was vacuum-dried at 200.degree. C. and submitted for
analysis.
Analysis: Calc'd. for C.sub.133 H.sub.62 N.sub.7 O.sub.35 S.sub.4 :
C, 65.30; H, 2.56; N, 4.01; O, 22.89; S, 4.24. Found: C, 63.90; H,
2.74; N, 4.70; O, - - - ; S, - - - .
EXAMPLE 37
Preparation of Anhydride-Terminated Oligomeric Polyimide (BTOD-4).
Reaction of BTCA and SDA-3,3 (9:8).
According to the procedure used for Example 32, there was allowed
to react BTCA (14.5003 g., 0.045 mole) and SDA-3,3 (9.9324 g., 0.04
mole) in 90 ml. of m-cresol and 20 ml. of benzene. There was
obtained the oligomer, BTOD-4, as a light-yellow solid, 21.4 g.
(95%) which was soluble in m-cresol, DMAC, DMF and sulfolane. It
began to melt at 265.degree. C. with the evolution of small amounts
of gas, but was not melted completely by 300.degree. C. and did not
harden during 15 minutes at 300.degree. C. The lowest temperature
at which a sample melted completely when dropped onto a preheated
block was 270.degree. C. The TGA in air data are given in Table
I.
A small sample vacuum-dried at 200.degree. C. was submitted for
analysis.
Analysis: Calc'd. for C.sub.249 H.sub.118 N.sub.15 O.sub.63 S.sub.8
: C, 65.24; H, 2.60; N, 4.58; O, 21.99; S, 5.60. Found: C, 63.99;
H, 2.73; N, 4.95; O, - - - ; S - - - .
EXAMPLE 38
Preparation of Anhydride-Terminated Oligomeric Polyimide (BTOD-5).
Reaction of BTCA and DAPB-3,3 (5:4).
According to the procedure used for Example 32, there was allowed
to react BTCA (4.0279 g., 0.0125 mole) and DAPB-3,3 (2.9223 g.,
0.01 mole) in 40 ml. of m-cresol and 10 ml. of benzene. There was
obtained the oligomer BTOD-5 (5.7678 g., 80%) as a light-yellow
powder which was soluble in m-cresol, DMAC, sulfolane and dioxane.
On a Fisher-Johns melting point apparatus BTOD-5 melted over the
range of 190.degree.-205.degree. C. with gas evolution and did not
harden during 10 minutes at 300.degree. C. The lowest temperature
at which a sample melted completely when dropped onto a preheated
block was 200.degree. C. The TGA in air data are given in Table
I.
Analysis: Calc'd. for C.sub.157 H.sub.78 N.sub.8 O.sub.35 :
C, 71.52; H, 2.98; N, 4.25; O, 21.24. Found: C, 71.41; H, 3.21; N,
4.46; O, - - - .
EXAMPLE 39
Preparation of Anhydride-Terminated Oligomeric Polyimide (BTOD-6).
Reaction of BTCA and DAPB-3,3 (9:8).
According to the procedure used for Example 32, there was allowed
to react BTCA (3.6251 g., 0.01125 mole) and DAPB-3,3 (2.9223 g.
0.01 mole) in 40 ml. of m-cresol and 10 ml. of benzene. There was
obtained BTOD-6 (5.6071 g., 90%) as a light-yellow powder which was
soluble in m-cresol, DMAC, sulfolane and dioxane. On a Fisher-Johns
melting point apparatus BTOD-6 melted from 185.degree.-215.degree.
C. with some evolution of gas and did not harden during 10 minutes
at 300.degree. C. The lowest temperature at which a sample would
completely melt when dropped onto a preheated block was 210.degree.
C. The TGA in air data are given in Table I.
Analysis: Calc'd. for C.sub.297 H.sub.150 N.sub.16 O.sub.63 : C,
72.03; H, 3.09; N, 4.53; O, 20.35. Found: C, 71.09; H, 3.22; N,
4.60; O, - - - .
The TGA's of each oligomer of Examples were performed in air at a
heating rate of 10.degree. C./minute. The data are summarized in
Table 4.
TABLE I
__________________________________________________________________________
TGA IN AIR DATA FOR OLIGOMERIC POLYIMIDES
__________________________________________________________________________
Oligomer TGA: Percent Residue at
__________________________________________________________________________
(Ex. No.) 200.degree. C. 300.degree. C. 400.degree. C. 500.degree.
C. 600.degree. C. 700.degree. C. 800.degree. C.
__________________________________________________________________________
BTAP-3 (29) 100 100 100 99 88 51 0 BTAP-5R (30) 100 100 99 97 82 0
0 BTAP-6 (31) 100 100 99 96 80 0 0 BTAT-4 (32) 100 100 99 98 84 25
0 BTAT-5 (33) 100 100 99 98 87 0 0 BTAT-6 (34) 100 100 100 99 80 20
0 BTAT-7 (35) 100 100 100 99 77 0 0 BTOD-3 (36) 98 97 96 93 74 0 0
BTOD-4 (37) 100 98 98 96 75 0 0 BTOD-5 (38) 98 97 96 95 83 0 0
BTOD-6 (39) 98 98 97 96 81 0 0
__________________________________________________________________________
EXAMPLE 40
Preparation of Polyimide (PI-20). Reaction of BTCA and DAPB-3,3
(1:1) under Nitrogen.
In a m-cresol:benzene azeotropic apparatus equipped with provision
for nitrogen inlet and outlet, there was placed BTCA (3.222 g.,
0.01 mole) with 25 ml. of m-cresol and 10 ml. of benzene. The
mixture was warmed until solution occurred; then a solution of
DAPB-3,3 (2.923 g., 0.01 mole) in 15 ml. of m-cresol was added. The
solution was refluxed for 4 hours under nitrogen and 0.4 ml. of
water was collected. Then the benzene was distilled off and the
temperature was raised to the reflux temperature of m-cresol. The
reaction mixture was refluxed under nitrogen for 24 hours and then
a small sample was removed and the polymer was precipitated with
methanol to give PI-20A, whose .eta.inh, after vacuum-drying at
70.degree. C., was 0.41 dl./g. as a 0.5% solution in m-cresol. The
infrared spectrum of PI-20A was consistent with the structure
expected for a completely cyclized polyimide.
Further bodying of PI-20 by refluxing in a m-cresol under nitrogen
was continued to a total of 68 hours, after which a small sample
was removed and the polymer precipitated with methanol to yield
PI-20B, whose .eta.inh (0.5% m-cresol) was 0.742 dl./g. After
refluxing to a total of 86 hours, a trace amount of gelled material
was found in the flask and reflux was discontinued. The polymer was
precipitated with methanol to give PI-20C, whose .eta.inh (0.5%
m-cresol) was 0.825 dl./g. PI-20C was soluble in m-cresol, DMAC,
sulfolane and dioxane. Its TGA in air showed a minor break at
475.degree. C. and inflection point at about 575.degree. C.
Analysis: Calc'd. for (C.sub.35 H.sub.18 N.sub.2 O.sub.7) :
(PI-20A) C, 72.66; H, 3.14; N, 4.84; O, 19.36. Found: C, 72.18; H,
3.35; N, 4.90; O, - - - .
The elemental analysis of the polymer is in excellent agreement
with the values calculated for a substantially or completely
cyclized polyimide of high molecular weight.
* * * * *